Update clang to r339409.

Change-Id: I800772d2d838223be1f6b40d490c4591b937fca2
diff --git a/linux-x64/clang/include/llvm/MC/MCInstrAnalysis.h b/linux-x64/clang/include/llvm/MC/MCInstrAnalysis.h
index dd3e1df..0777add 100644
--- a/linux-x64/clang/include/llvm/MC/MCInstrAnalysis.h
+++ b/linux-x64/clang/include/llvm/MC/MCInstrAnalysis.h
@@ -22,6 +22,9 @@
 
 namespace llvm {
 
+class MCRegisterInfo;
+class Triple;
+
 class MCInstrAnalysis {
 protected:
   friend class Target;
@@ -60,11 +63,56 @@
     return Info->get(Inst.getOpcode()).isTerminator();
   }
 
-  /// \brief Given a branch instruction try to get the address the branch
+  /// Returns true if at least one of the register writes performed by
+  /// \param Inst implicitly clears the upper portion of all super-registers.
+  ///
+  /// Example: on X86-64, a write to EAX implicitly clears the upper half of
+  /// RAX. Also (still on x86) an XMM write perfomed by an AVX 128-bit
+  /// instruction implicitly clears the upper portion of the correspondent
+  /// YMM register.
+  ///
+  /// This method also updates an APInt which is used as mask of register
+  /// writes. There is one bit for every explicit/implicit write performed by
+  /// the instruction. If a write implicitly clears its super-registers, then
+  /// the corresponding bit is set (vic. the corresponding bit is cleared).
+  ///
+  /// The first bits in the APint are related to explicit writes. The remaining
+  /// bits are related to implicit writes. The sequence of writes follows the
+  /// machine operand sequence. For implicit writes, the sequence is defined by
+  /// the MCInstrDesc.
+  ///
+  /// The assumption is that the bit-width of the APInt is correctly set by
+  /// the caller. The default implementation conservatively assumes that none of
+  /// the writes clears the upper portion of a super-register.
+  virtual bool clearsSuperRegisters(const MCRegisterInfo &MRI,
+                                    const MCInst &Inst,
+                                    APInt &Writes) const;
+
+  /// Returns true if \param Inst is a dependency breaking instruction for the
+  /// given subtarget.
+  ///
+  /// The value computed by a dependency breaking instruction is not dependent
+  /// on the inputs. An example of dependency breaking instruction on X86 is
+  /// `XOR %eax, %eax`.
+  /// TODO: In future, we could implement an alternative approach where this
+  /// method returns `true` if the input instruction is not dependent on
+  /// some/all of its input operands. An APInt mask could then be used to
+  /// identify independent operands.
+  virtual bool isDependencyBreaking(const MCSubtargetInfo &STI,
+                                    const MCInst &Inst) const;
+
+  /// Given a branch instruction try to get the address the branch
   /// targets. Return true on success, and the address in Target.
   virtual bool
   evaluateBranch(const MCInst &Inst, uint64_t Addr, uint64_t Size,
                  uint64_t &Target) const;
+
+  /// Returns (PLT virtual address, GOT virtual address) pairs for PLT entries.
+  virtual std::vector<std::pair<uint64_t, uint64_t>>
+  findPltEntries(uint64_t PltSectionVA, ArrayRef<uint8_t> PltContents,
+                 uint64_t GotPltSectionVA, const Triple &TargetTriple) const {
+    return {};
+  }
 };
 
 } // end namespace llvm