Import prebuilt clang toolchain for linux.
diff --git a/linux-x64/clang/include/llvm/Support/Process.h b/linux-x64/clang/include/llvm/Support/Process.h
new file mode 100644
index 0000000..82b0d9f
--- /dev/null
+++ b/linux-x64/clang/include/llvm/Support/Process.h
@@ -0,0 +1,200 @@
+//===- llvm/Support/Process.h -----------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+/// \file
+///
+/// Provides a library for accessing information about this process and other
+/// processes on the operating system. Also provides means of spawning
+/// subprocess for commands. The design of this library is modeled after the
+/// proposed design of the Boost.Process library, and is design specifically to
+/// follow the style of standard libraries and potentially become a proposal
+/// for a standard library.
+///
+/// This file declares the llvm::sys::Process class which contains a collection
+/// of legacy static interfaces for extracting various information about the
+/// current process. The goal is to migrate users of this API over to the new
+/// interfaces.
+///
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_SUPPORT_PROCESS_H
+#define LLVM_SUPPORT_PROCESS_H
+
+#include "llvm/ADT/Optional.h"
+#include "llvm/Config/llvm-config.h"
+#include "llvm/Support/Allocator.h"
+#include "llvm/Support/Chrono.h"
+#include "llvm/Support/DataTypes.h"
+#include <system_error>
+
+namespace llvm {
+template <typename T> class ArrayRef;
+class StringRef;
+
+namespace sys {
+
+
+/// \brief A collection of legacy interfaces for querying information about the
+/// current executing process.
+class Process {
+public:
+  static unsigned getPageSize();
+
+  /// \brief Return process memory usage.
+  /// This static function will return the total amount of memory allocated
+  /// by the process. This only counts the memory allocated via the malloc,
+  /// calloc and realloc functions and includes any "free" holes in the
+  /// allocated space.
+  static size_t GetMallocUsage();
+
+  /// This static function will set \p user_time to the amount of CPU time
+  /// spent in user (non-kernel) mode and \p sys_time to the amount of CPU
+  /// time spent in system (kernel) mode.  If the operating system does not
+  /// support collection of these metrics, a zero duration will be for both
+  /// values.
+  /// \param elapsed Returns the system_clock::now() giving current time
+  /// \param user_time Returns the current amount of user time for the process
+  /// \param sys_time Returns the current amount of system time for the process
+  static void GetTimeUsage(TimePoint<> &elapsed,
+                           std::chrono::nanoseconds &user_time,
+                           std::chrono::nanoseconds &sys_time);
+
+  /// This function makes the necessary calls to the operating system to
+  /// prevent core files or any other kind of large memory dumps that can
+  /// occur when a program fails.
+  /// @brief Prevent core file generation.
+  static void PreventCoreFiles();
+
+  /// \brief true if PreventCoreFiles has been called, false otherwise.
+  static bool AreCoreFilesPrevented();
+
+  // This function returns the environment variable \arg name's value as a UTF-8
+  // string. \arg Name is assumed to be in UTF-8 encoding too.
+  static Optional<std::string> GetEnv(StringRef name);
+
+  /// This function searches for an existing file in the list of directories
+  /// in a PATH like environment variable, and returns the first file found,
+  /// according to the order of the entries in the PATH like environment
+  /// variable.  If an ignore list is specified, then any folder which is in
+  /// the PATH like environment variable but is also in IgnoreList is not
+  /// considered.
+  static Optional<std::string> FindInEnvPath(StringRef EnvName,
+                                             StringRef FileName,
+                                             ArrayRef<std::string> IgnoreList);
+
+  static Optional<std::string> FindInEnvPath(StringRef EnvName,
+                                             StringRef FileName);
+
+  /// This function returns a SmallVector containing the arguments passed from
+  /// the operating system to the program.  This function expects to be handed
+  /// the vector passed in from main.
+  static std::error_code
+  GetArgumentVector(SmallVectorImpl<const char *> &Args,
+                    ArrayRef<const char *> ArgsFromMain,
+                    SpecificBumpPtrAllocator<char> &ArgAllocator);
+
+  // This functions ensures that the standard file descriptors (input, output,
+  // and error) are properly mapped to a file descriptor before we use any of
+  // them.  This should only be called by standalone programs, library
+  // components should not call this.
+  static std::error_code FixupStandardFileDescriptors();
+
+  // This function safely closes a file descriptor.  It is not safe to retry
+  // close(2) when it returns with errno equivalent to EINTR; this is because
+  // *nixen cannot agree if the file descriptor is, in fact, closed when this
+  // occurs.
+  //
+  // N.B. Some operating systems, due to thread cancellation, cannot properly
+  // guarantee that it will or will not be closed one way or the other!
+  static std::error_code SafelyCloseFileDescriptor(int FD);
+
+  /// This function determines if the standard input is connected directly
+  /// to a user's input (keyboard probably), rather than coming from a file
+  /// or pipe.
+  static bool StandardInIsUserInput();
+
+  /// This function determines if the standard output is connected to a
+  /// "tty" or "console" window. That is, the output would be displayed to
+  /// the user rather than being put on a pipe or stored in a file.
+  static bool StandardOutIsDisplayed();
+
+  /// This function determines if the standard error is connected to a
+  /// "tty" or "console" window. That is, the output would be displayed to
+  /// the user rather than being put on a pipe or stored in a file.
+  static bool StandardErrIsDisplayed();
+
+  /// This function determines if the given file descriptor is connected to
+  /// a "tty" or "console" window. That is, the output would be displayed to
+  /// the user rather than being put on a pipe or stored in a file.
+  static bool FileDescriptorIsDisplayed(int fd);
+
+  /// This function determines if the given file descriptor is displayd and
+  /// supports colors.
+  static bool FileDescriptorHasColors(int fd);
+
+  /// This function determines the number of columns in the window
+  /// if standard output is connected to a "tty" or "console"
+  /// window. If standard output is not connected to a tty or
+  /// console, or if the number of columns cannot be determined,
+  /// this routine returns zero.
+  static unsigned StandardOutColumns();
+
+  /// This function determines the number of columns in the window
+  /// if standard error is connected to a "tty" or "console"
+  /// window. If standard error is not connected to a tty or
+  /// console, or if the number of columns cannot be determined,
+  /// this routine returns zero.
+  static unsigned StandardErrColumns();
+
+  /// This function determines whether the terminal connected to standard
+  /// output supports colors. If standard output is not connected to a
+  /// terminal, this function returns false.
+  static bool StandardOutHasColors();
+
+  /// This function determines whether the terminal connected to standard
+  /// error supports colors. If standard error is not connected to a
+  /// terminal, this function returns false.
+  static bool StandardErrHasColors();
+
+  /// Enables or disables whether ANSI escape sequences are used to output
+  /// colors. This only has an effect on Windows.
+  /// Note: Setting this option is not thread-safe and should only be done
+  /// during initialization.
+  static void UseANSIEscapeCodes(bool enable);
+
+  /// Whether changing colors requires the output to be flushed.
+  /// This is needed on systems that don't support escape sequences for
+  /// changing colors.
+  static bool ColorNeedsFlush();
+
+  /// This function returns the colorcode escape sequences.
+  /// If ColorNeedsFlush() is true then this function will change the colors
+  /// and return an empty escape sequence. In that case it is the
+  /// responsibility of the client to flush the output stream prior to
+  /// calling this function.
+  static const char *OutputColor(char c, bool bold, bool bg);
+
+  /// Same as OutputColor, but only enables the bold attribute.
+  static const char *OutputBold(bool bg);
+
+  /// This function returns the escape sequence to reverse forground and
+  /// background colors.
+  static const char *OutputReverse();
+
+  /// Resets the terminals colors, or returns an escape sequence to do so.
+  static const char *ResetColor();
+
+  /// Get the result of a process wide random number generator. The
+  /// generator will be automatically seeded in non-deterministic fashion.
+  static unsigned GetRandomNumber();
+};
+
+}
+}
+
+#endif