This is a mostly straight-forward rebase of our patches on top of
13.1.0. The spec files needed a change, as GCC no longer supports STABS
debug information, but we were building GCC with support for it.
Highlights of this release include static `operator()`, The Equality
Operator You Are Looking For and extended `constexpr` support.
The biggest difference is that -m32 is no longer important, and in fact
breaks every 64-bit setup.
Also, defining ENABLE_UNICODE_DATA, ENABLE_COMPILETIME_FORMAT_CHECK, and
__SSE__ makes some code "visible" in the #ifdef sense, which improves
syntax highlighting.