Import prebuilt clang toolchain for linux.
diff --git a/linux-x64/clang/include/llvm/MC/MCSection.h b/linux-x64/clang/include/llvm/MC/MCSection.h
new file mode 100644
index 0000000..2771b1e
--- /dev/null
+++ b/linux-x64/clang/include/llvm/MC/MCSection.h
@@ -0,0 +1,187 @@
+//===- MCSection.h - Machine Code Sections ----------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file declares the MCSection class.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_MC_MCSECTION_H
+#define LLVM_MC_MCSECTION_H
+
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/ilist.h"
+#include "llvm/MC/MCFragment.h"
+#include "llvm/MC/SectionKind.h"
+#include <cassert>
+#include <utility>
+
+namespace llvm {
+
+class MCAsmInfo;
+class MCContext;
+class MCExpr;
+class MCSymbol;
+class raw_ostream;
+class Triple;
+
+template <> struct ilist_alloc_traits<MCFragment> {
+  static void deleteNode(MCFragment *V);
+};
+
+/// Instances of this class represent a uniqued identifier for a section in the
+/// current translation unit.  The MCContext class uniques and creates these.
+class MCSection {
+public:
+  enum SectionVariant { SV_COFF = 0, SV_ELF, SV_MachO, SV_Wasm };
+
+  /// \brief Express the state of bundle locked groups while emitting code.
+  enum BundleLockStateType {
+    NotBundleLocked,
+    BundleLocked,
+    BundleLockedAlignToEnd
+  };
+
+  using FragmentListType = iplist<MCFragment>;
+
+  using const_iterator = FragmentListType::const_iterator;
+  using iterator = FragmentListType::iterator;
+
+  using const_reverse_iterator = FragmentListType::const_reverse_iterator;
+  using reverse_iterator = FragmentListType::reverse_iterator;
+
+private:
+  MCSymbol *Begin;
+  MCSymbol *End = nullptr;
+  /// The alignment requirement of this section.
+  unsigned Alignment = 1;
+  /// The section index in the assemblers section list.
+  unsigned Ordinal = 0;
+  /// The index of this section in the layout order.
+  unsigned LayoutOrder;
+
+  /// \brief Keeping track of bundle-locked state.
+  BundleLockStateType BundleLockState = NotBundleLocked;
+
+  /// \brief Current nesting depth of bundle_lock directives.
+  unsigned BundleLockNestingDepth = 0;
+
+  /// \brief We've seen a bundle_lock directive but not its first instruction
+  /// yet.
+  bool BundleGroupBeforeFirstInst : 1;
+
+  /// Whether this section has had instructions emitted into it.
+  bool HasInstructions : 1;
+
+  bool IsRegistered : 1;
+
+  MCDummyFragment DummyFragment;
+
+  FragmentListType Fragments;
+
+  /// Mapping from subsection number to insertion point for subsection numbers
+  /// below that number.
+  SmallVector<std::pair<unsigned, MCFragment *>, 1> SubsectionFragmentMap;
+
+protected:
+  SectionVariant Variant;
+  SectionKind Kind;
+
+  MCSection(SectionVariant V, SectionKind K, MCSymbol *Begin);
+  ~MCSection();
+
+public:
+  MCSection(const MCSection &) = delete;
+  MCSection &operator=(const MCSection &) = delete;
+
+  SectionKind getKind() const { return Kind; }
+
+  SectionVariant getVariant() const { return Variant; }
+
+  MCSymbol *getBeginSymbol() { return Begin; }
+  const MCSymbol *getBeginSymbol() const {
+    return const_cast<MCSection *>(this)->getBeginSymbol();
+  }
+  void setBeginSymbol(MCSymbol *Sym) {
+    assert(!Begin);
+    Begin = Sym;
+  }
+  MCSymbol *getEndSymbol(MCContext &Ctx);
+  bool hasEnded() const;
+
+  unsigned getAlignment() const { return Alignment; }
+  void setAlignment(unsigned Value) { Alignment = Value; }
+
+  unsigned getOrdinal() const { return Ordinal; }
+  void setOrdinal(unsigned Value) { Ordinal = Value; }
+
+  unsigned getLayoutOrder() const { return LayoutOrder; }
+  void setLayoutOrder(unsigned Value) { LayoutOrder = Value; }
+
+  BundleLockStateType getBundleLockState() const { return BundleLockState; }
+  void setBundleLockState(BundleLockStateType NewState);
+  bool isBundleLocked() const { return BundleLockState != NotBundleLocked; }
+
+  bool isBundleGroupBeforeFirstInst() const {
+    return BundleGroupBeforeFirstInst;
+  }
+  void setBundleGroupBeforeFirstInst(bool IsFirst) {
+    BundleGroupBeforeFirstInst = IsFirst;
+  }
+
+  bool hasInstructions() const { return HasInstructions; }
+  void setHasInstructions(bool Value) { HasInstructions = Value; }
+
+  bool isRegistered() const { return IsRegistered; }
+  void setIsRegistered(bool Value) { IsRegistered = Value; }
+
+  MCSection::FragmentListType &getFragmentList() { return Fragments; }
+  const MCSection::FragmentListType &getFragmentList() const {
+    return const_cast<MCSection *>(this)->getFragmentList();
+  }
+
+  /// Support for MCFragment::getNextNode().
+  static FragmentListType MCSection::*getSublistAccess(MCFragment *) {
+    return &MCSection::Fragments;
+  }
+
+  const MCDummyFragment &getDummyFragment() const { return DummyFragment; }
+  MCDummyFragment &getDummyFragment() { return DummyFragment; }
+
+  iterator begin() { return Fragments.begin(); }
+  const_iterator begin() const { return Fragments.begin(); }
+
+  iterator end() { return Fragments.end(); }
+  const_iterator end() const { return Fragments.end(); }
+
+  reverse_iterator rbegin() { return Fragments.rbegin(); }
+  const_reverse_iterator rbegin() const { return Fragments.rbegin(); }
+
+  reverse_iterator rend() { return Fragments.rend(); }
+  const_reverse_iterator rend() const  { return Fragments.rend(); }
+
+  MCSection::iterator getSubsectionInsertionPoint(unsigned Subsection);
+
+  void dump() const;
+
+  virtual void PrintSwitchToSection(const MCAsmInfo &MAI, const Triple &T,
+                                    raw_ostream &OS,
+                                    const MCExpr *Subsection) const = 0;
+
+  /// Return true if a .align directive should use "optimized nops" to fill
+  /// instead of 0s.
+  virtual bool UseCodeAlign() const = 0;
+
+  /// Check whether this section is "virtual", that is has no actual object
+  /// file contents.
+  virtual bool isVirtualSection() const = 0;
+};
+
+} // end namespace llvm
+
+#endif // LLVM_MC_MCSECTION_H