Re-commit r152202 hopefully fixing the MSVC linker error.

Original commit message:
Use uint16_t to store InstrNameIndices in MCInstrInfo. Add asserts to protect all 16-bit string table offsets. Also make sure the string to offset table string is not larger than 65536 characters since larger string literals aren't portable.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@152296 91177308-0d34-0410-b5e6-96231b3b80d8

utils/TableGen/StringToOffsetTable.h

@@ -40,6 +40,9 @@ public:
   }
   
   void EmitString(raw_ostream &O) {
+    assert(AggregateString.size() <= 65536 &&
+           "Aggregate string too large to be portable");
+
     // Escape the string.
     SmallString<256> Str;
     raw_svector_ostream(Str).write_escaped(AggregateString);