This comes from the Ruby fiber maintainer. It doesn't require compiling a
couple files without optimization, and it was able to get through a make
test run without crashing on sparc64, which uses the copy coroutine fiber
implementation.
OK kn@
Also add local patch to compile a couple of fiber-related
files with -O0, as that is also needed to prevent the crash
on sparc64.
Add a second distpatch to fix a regression in 2.7.2 causing
a crash when calling ffi_closure_free.
OK kn@
