Implement !cast.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@71794 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/utils/TableGen/TGLexer.cpp b/utils/TableGen/TGLexer.cpp
index 5e96e50..43afae9 100644
--- a/utils/TableGen/TGLexer.cpp
+++ b/utils/TableGen/TGLexer.cpp
@@ -449,7 +449,7 @@
   if (Len == 10 && !memcmp(Start, "nameconcat", 10)) return tgtok::XNameConcat;
 //   if (Len == 5 && !memcmp(Start, "subst", 5)) return tgtok::XSubst;
 //   if (Len == 7 && !memcmp(Start, "foreach", 7)) return tgtok::XForEach;
-//   if (Len == 4 && !memcmp(Start, "cast", 4)) return tgtok::XCast;
+  if (Len == 4 && !memcmp(Start, "cast", 4)) return tgtok::XCast;
 
   return ReturnError(Start-1, "Unknown operator");
 }