Fix for PR7040: Don't try to compute the LLVM type for a function where it
isn't possible to compute.

This patch is mostly refactoring; the key change is the addition of the code
starting with the comment, "Check whether the function has a computable LLVM
signature."  The solution here is essentially the same as the way the
vtable code handles such functions.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@105151 91177308-0d34-0410-b5e6-96231b3b80d8
8 files changed