Split out the "empty" case for compound statement into a separate ctor.

Move the ASTContext-dependent version out of line.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@159717 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaLambda.cpp b/lib/Sema/SemaLambda.cpp
index 6c78d83..ab5640c 100644
--- a/lib/Sema/SemaLambda.cpp
+++ b/lib/Sema/SemaLambda.cpp
@@ -947,9 +947,7 @@
 
   // Add a fake function body to the block. IR generation is responsible
   // for filling in the actual body, which cannot be expressed as an AST.
-  Block->setBody(new (Context) CompoundStmt(Context, 0, 0, 
-                                            ConvLocation,
-                                            ConvLocation));
+  Block->setBody(new (Context) CompoundStmt(ConvLocation));
 
   // Create the block literal expression.
   Expr *BuildBlock = new (Context) BlockExpr(Block, Conv->getConversionType());