Switch a cast to a dyn_cast and check the pointer before using.  Fixes a crash
in the following code:

void test4(bool (&x)(void)) {
  while (x);
}



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@145918 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed