Fix the clang bootstrap and Jay's testcase from llvm-dev by being completely

Fix the clang bootstrap and Jay's testcase from llvm-dev by being completely
conservative when converting a functiontype to IR when in a "pointer within
a struct" context.  This has the unfortunate sideeffect of compiling all
function pointers inside of structs into "{}*" which, though correct, is
ugly.  This has the positive side effect of being correct, and it is pretty
straight-forward to improve on this.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@134861 91177308-0d34-0410-b5e6-96231b3b80d8