Parse and print opt_size note.

llvm-svn: 55740
diff --git a/llvm/lib/AsmParser/LLLexer.cpp b/llvm/lib/AsmParser/LLLexer.cpp
index 6af0ab4..51e63a8 100644
--- a/llvm/lib/AsmParser/LLLexer.cpp
+++ b/llvm/lib/AsmParser/LLLexer.cpp
@@ -501,7 +501,7 @@
   KEYWORD("inline", INLINE);
   KEYWORD("always", ALWAYS);
   KEYWORD("never", NEVER);
-  KEYWORD("optimizeforsize", OPTIMIZEFORSIZE);
+  KEYWORD("opt_size", OPTIMIZEFORSIZE);
 
   KEYWORD("type", TYPE);
   KEYWORD("opaque", OPAQUE);