[ms-inline asm] Add a few typedefs to simplify future changes.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165324 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/Mips/AsmParser/MipsAsmParser.cpp b/lib/Target/Mips/AsmParser/MipsAsmParser.cpp
index f2800d3..6605fe4 100644
--- a/lib/Target/Mips/AsmParser/MipsAsmParser.cpp
+++ b/lib/Target/Mips/AsmParser/MipsAsmParser.cpp
@@ -371,7 +371,7 @@
   MCInst Inst;
   unsigned Kind;
   unsigned ErrorInfo;
-  SmallVector<std::pair< unsigned, std::string >, 4> MapAndConstraints;
+  MatchInstMapAndConstraints MapAndConstraints;
   unsigned MatchResult = MatchInstructionImpl(Operands, Kind, Inst,
                                               MapAndConstraints, ErrorInfo,
                                               /*matchingInlineAsm*/ false);