switch GC_LABEL to use an MCSymbol operand instead of a label ID operand.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@98474 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/GCMetadataPrinter.cpp

@@ -12,7 +12,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/CodeGen/GCMetadataPrinter.h"
-
+class MCAsmInfo;
 using namespace llvm;
 
 GCMetadataPrinter::GCMetadataPrinter() { }