Add support for embedded metadata to LLVM. This introduces two new types of

Constant, MDString and MDNode which can only be used by globals with a name
that starts with "llvm." or as arguments to a function with the same naming
restriction.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@68420 91177308-0d34-0410-b5e6-96231b3b80d8

lib/AsmParser/LLLexer.cpp

@@ -265,6 +265,7 @@ lltok::Kind LLLexer::LexToken() {
   case ';':
     SkipLineComment();
     return LexToken();
+  case '!': return lltok::Metadata;
   case '0': case '1': case '2': case '3': case '4':
   case '5': case '6': case '7': case '8': case '9':
   case '-':