Improve c-style cast detection.

Before:
return (my_int) aaaa;
template <> void f<int>(int i)SOME_ANNOTATION;
f("aaaa" SOME_MACRO(aaaa)"aaaa");

After:
return (my_int)aaaa;
template <> void f<int>(int i) SOME_ANNOTATION;
f("aaaa" SOME_MACRO(aaaa) "aaaa");

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@183389 91177308-0d34-0410-b5e6-96231b3b80d8