unit tests pass
almost there...
gccxml integration tests now work
clang: Enum template arguments should never show up as ints

Sometimes clang returns enum template arguments as the underlying
integer.  If this happens, we convert back to the name.

libclang synced from https://github.com/xdress/clang/commit/8ab7c572b32825fcb13e8d5fbaf54c496b3358fe.