Fix the required args count for variadic blocks.

We were emitting calls to blocks as if all arguments were
required --- i.e. with signature (A,B,C,D,...) rather than
(A,B,...).  This patch fixes that and accounts for the
implicit block-context argument as a required argument.
In addition, this patch changes the function type under which
we call unprototyped functions on platforms like x86-64 that
guarantee compatibility of variadic functions with unprototyped
function types;  previously we would always call such functions
under the LLVM type T (...)*, but now we will call them under
the type T (A,B,C,D,...)*.  This last change should have no
material effect except for making the type conventions more
explicit;  it was a side-effect of the most convenient implementation.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@169588 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CGBlocks.cpp b/lib/CodeGen/CGBlocks.cpp
index d181da2..8dacf15 100644
--- a/lib/CodeGen/CGBlocks.cpp
+++ b/lib/CodeGen/CGBlocks.cpp
@@ -905,7 +905,7 @@
 
   const FunctionType *FuncTy = FnType->castAs<FunctionType>();
   const CGFunctionInfo &FnInfo =
-    CGM.getTypes().arrangeFreeFunctionCall(Args, FuncTy);
+    CGM.getTypes().arrangeBlockFunctionCall(Args, FuncTy);
 
   // Cast the function pointer to the right type.
   llvm::Type *BlockFTy = CGM.getTypes().GetFunctionType(FnInfo);