Distinguish more carefully between free functions and C++ instance methods
in the ABI arrangement, and leave a hook behind so that we can easily
tweak CCs on platforms that use different CCs by default for C++
instance methods.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@159894 91177308-0d34-0410-b5e6-96231b3b80d8
12 files changed