Add a very basic implemenation of global blocks. This needs to be cleaned up.

llvm-svn: 64387
diff --git a/clang/lib/CodeGen/CGExprConstant.cpp b/clang/lib/CodeGen/CGExprConstant.cpp
index 1f6da8a..91153f7 100644
--- a/clang/lib/CodeGen/CGExprConstant.cpp
+++ b/clang/lib/CodeGen/CGExprConstant.cpp
@@ -371,6 +371,10 @@
     return Visit(E->getSubExpr());
   }
     
+  llvm::Constant *VisitBlockExpr(const BlockExpr *E) {
+    return CGM.GetAddrOfGlobalBlock(E);
+  }
+  
   // Utility methods
   const llvm::Type *ConvertType(QualType T) {
     return CGM.getTypes().ConvertType(T);