Fix <rdar://problem/6312683> clang block rewriter:

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@58011 91177308-0d34-0410-b5e6-96231b3b80d8

Driver/RewriteBlocks.cpp

@@ -804,7 +804,6 @@ bool RewriteBlocks::PointerTypeTakesAnyBlockArguments(QualType QT) {
   const PointerType *PT = QT->getAsPointerType();
   if (PT) {
     FTP = PT->getPointeeType()->getAsFunctionTypeProto();
-    assert(FTP && "BlockPointerTypeTakeAnyBlockArguments(): not a function pointer type");
   } else {
     const BlockPointerType *BPT = QT->getAsBlockPointerType();
     assert(BPT && "BlockPointerTypeTakeAnyBlockArguments(): not a block pointer type");