Update clang to r339409.

Change-Id: I800772d2d838223be1f6b40d490c4591b937fca2
diff --git a/linux-x64/clang/include/llvm/MC/MCParser/MCTargetAsmParser.h b/linux-x64/clang/include/llvm/MC/MCParser/MCTargetAsmParser.h
index d628794..2d188a6 100644
--- a/linux-x64/clang/include/llvm/MC/MCParser/MCTargetAsmParser.h
+++ b/linux-x64/clang/include/llvm/MC/MCParser/MCTargetAsmParser.h
@@ -14,6 +14,7 @@
 #include "llvm/MC/MCExpr.h"
 #include "llvm/MC/MCInstrInfo.h"
 #include "llvm/MC/MCParser/MCAsmLexer.h"
+#include "llvm/MC/MCParser/MCParsedAsmOperand.h"
 #include "llvm/MC/MCParser/MCAsmParserExtension.h"
 #include "llvm/MC/MCTargetOptions.h"
 #include "llvm/Support/SMLoc.h"
@@ -133,6 +134,53 @@
   MatchOperand_ParseFail // operand matched but had errors
 };
 
+enum class DiagnosticPredicateTy {
+  Match,
+  NearMatch,
+  NoMatch,
+};
+
+// When an operand is parsed, the assembler will try to iterate through a set of
+// possible operand classes that the operand might match and call the
+// corresponding PredicateMethod to determine that.
+//
+// If there are two AsmOperands that would give a specific diagnostic if there
+// is no match, there is currently no mechanism to distinguish which operand is
+// a closer match. The DiagnosticPredicate distinguishes between 'completely
+// no match' and 'near match', so the assembler can decide whether to give a
+// specific diagnostic, or use 'InvalidOperand' and continue to find a
+// 'better matching' diagnostic.
+//
+// For example:
+//    opcode opnd0, onpd1, opnd2
+//
+// where:
+//    opnd2 could be an 'immediate of range [-8, 7]'
+//    opnd2 could be a  'register + shift/extend'.
+//
+// If opnd2 is a valid register, but with a wrong shift/extend suffix, it makes
+// little sense to give a diagnostic that the operand should be an immediate
+// in range [-8, 7].
+//
+// This is a light-weight alternative to the 'NearMissInfo' approach
+// below which collects *all* possible diagnostics. This alternative
+// is optional and fully backward compatible with existing
+// PredicateMethods that return a 'bool' (match or no match).
+struct DiagnosticPredicate {
+  DiagnosticPredicateTy Type;
+
+  explicit DiagnosticPredicate(bool Match)
+      : Type(Match ? DiagnosticPredicateTy::Match
+                   : DiagnosticPredicateTy::NearMatch) {}
+  DiagnosticPredicate(DiagnosticPredicateTy T) : Type(T) {}
+  DiagnosticPredicate(const DiagnosticPredicate &) = default;
+
+  operator bool() const { return Type == DiagnosticPredicateTy::Match; }
+  bool isMatch() const { return Type == DiagnosticPredicateTy::Match; }
+  bool isNearMatch() const { return Type == DiagnosticPredicateTy::NearMatch; }
+  bool isNoMatch() const { return Type == DiagnosticPredicateTy::NoMatch; }
+};
+
 // When matching of an assembly instruction fails, there may be multiple
 // encodings that are close to being a match. It's often ambiguous which one
 // the programmer intended to use, so we want to report an error which mentions
@@ -324,6 +372,11 @@
     SemaCallback = Callback;
   }
 
+  // Target-specific parsing of assembler-level variable assignment.
+  virtual bool parseAssignmentExpression(const MCExpr *&Res, SMLoc &EndLoc) {
+    return getParser().parseExpression(Res, EndLoc);
+  }
+
   virtual bool ParseRegister(unsigned &RegNo, SMLoc &StartLoc,
                              SMLoc &EndLoc) = 0;
 
@@ -401,6 +454,15 @@
   virtual void convertToMapAndConstraints(unsigned Kind,
                                           const OperandVector &Operands) = 0;
 
+  /// Returns whether two registers are equal and is used by the tied-operands
+  /// checks in the AsmMatcher. This method can be overridden allow e.g. a
+  /// sub- or super-register as the tied operand.
+  virtual bool regsEqual(const MCParsedAsmOperand &Op1,
+                         const MCParsedAsmOperand &Op2) const {
+    assert(Op1.isReg() && Op2.isReg() && "Operands not all regs");
+    return Op1.getReg() == Op2.getReg();
+  }
+
   // Return whether this parser uses assignment statements with equals tokens
   virtual bool equalIsAsmAssignment() { return true; };
   // Return whether this start of statement identifier is a label