Add -fobjc-gc and -fobjc-gc-only options to the driver.
Add corresponding enum in LangOptions.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@50387 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Basic/LangOptions.cpp b/lib/Basic/LangOptions.cpp
index f7fd91f..6119afc 100644
--- a/lib/Basic/LangOptions.cpp
+++ b/lib/Basic/LangOptions.cpp
@@ -30,7 +30,8 @@
   S.EmitBool((bool) NoExtensions);
   S.EmitBool((bool) CXXOperatorNames);             
   S.EmitBool((bool) ObjC1);
-  S.EmitBool((bool) ObjC2);             
+  S.EmitBool((bool) ObjC2);
+  S.EmitBool((unsigned) GC);
   S.EmitBool((bool) PascalStrings);
   S.EmitBool((bool) Boolean);
   S.EmitBool((bool) WritableStrings);
@@ -51,6 +52,7 @@
   CXXOperatorNames = D.ReadBool() ? 1 : 0;
   ObjC1 = D.ReadBool() ? 1 : 0;
   ObjC2 = D.ReadBool() ? 1 : 0;
+  GC = D.ReadInt();
   PascalStrings = D.ReadBool() ? 1 : 0;
   Boolean = D.ReadBool() ? 1 : 0;
   WritableStrings = D.ReadBool() ? 1 : 0;