Import prebuilt clang toolchain for linux.
diff --git a/linux-x64/clang/include/llvm/MC/MCSectionWasm.h b/linux-x64/clang/include/llvm/MC/MCSectionWasm.h
new file mode 100644
index 0000000..ab4cd7b
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+++ b/linux-x64/clang/include/llvm/MC/MCSectionWasm.h
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+//===- MCSectionWasm.h - Wasm 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 MCSectionWasm class.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_MC_MCSECTIONWASM_H
+#define LLVM_MC_MCSECTIONWASM_H
+
+#include "llvm/ADT/Twine.h"
+#include "llvm/MC/MCSection.h"
+#include "llvm/MC/MCSymbolWasm.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/raw_ostream.h"
+
+namespace llvm {
+
+class MCSymbol;
+
+/// This represents a section on wasm.
+class MCSectionWasm final : public MCSection {
+  /// This is the name of the section.  The referenced memory is owned by
+  /// TargetLoweringObjectFileWasm's WasmUniqueMap.
+  StringRef SectionName;
+
+  unsigned UniqueID;
+
+  const MCSymbolWasm *Group;
+
+  // The offset of the MC function/data section in the wasm code/data section.
+  // For data relocations the offset is relative to start of the data payload
+  // itself and does not include the size of the section header.
+  uint64_t SectionOffset = 0;
+
+  // For data sections, this is the index of of the corresponding wasm data
+  // segment
+  uint32_t SegmentIndex = 0;
+
+  friend class MCContext;
+  MCSectionWasm(StringRef Section, SectionKind K, const MCSymbolWasm *group,
+                unsigned UniqueID, MCSymbol *Begin)
+      : MCSection(SV_Wasm, K, Begin), SectionName(Section), UniqueID(UniqueID),
+        Group(group) {}
+
+  void setSectionName(StringRef Name) { SectionName = Name; }
+
+public:
+  ~MCSectionWasm();
+
+  /// Decides whether a '.section' directive should be printed before the
+  /// section name
+  bool ShouldOmitSectionDirective(StringRef Name, const MCAsmInfo &MAI) const;
+
+  StringRef getSectionName() const { return SectionName; }
+  const MCSymbolWasm *getGroup() const { return Group; }
+
+  void PrintSwitchToSection(const MCAsmInfo &MAI, const Triple &T,
+                            raw_ostream &OS,
+                            const MCExpr *Subsection) const override;
+  bool UseCodeAlign() const override;
+  bool isVirtualSection() const override;
+
+  bool isWasmData() const {
+    return Kind.isGlobalWriteableData() || Kind.isReadOnly();
+  }
+
+  bool isUnique() const { return UniqueID != ~0U; }
+  unsigned getUniqueID() const { return UniqueID; }
+
+  uint64_t getSectionOffset() const { return SectionOffset; }
+  void setSectionOffset(uint64_t Offset) { SectionOffset = Offset; }
+
+  uint32_t getSegmentIndex() const { return SegmentIndex; }
+  void setSegmentIndex(uint32_t Index) { SegmentIndex = Index; }
+
+  static bool classof(const MCSection *S) { return S->getVariant() == SV_Wasm; }
+};
+
+} // end namespace llvm
+
+#endif