Spit 5th bullet __invoke into function pointers and everything else because result_of doesn't deal with function pointers.
Spit 5th bullet __invoke into function pointers and everything else because result_of doesn't deal with function pointers.

git-svn-id: 756ef344af921d95d562d9e9f9389127a89a6314@131409 91177308-0d34-0410-b5e6-96231b3b80d8

llvm-mirror/libcxx,llvm-mirror/libcxx,llvm-mirror/libcxx,llvm-mirror/libcxx,llvm-mirror/libcxx