aarch64: mingw: fix support for posix threading

Currently without this --with-threads=pthread fails.

gcc/ChangeLog:

	* config/i386/mingw-pthread.h:
	rename to generic config/mingw/mingw-pthread.h
	* config.gcc [aarch64-*-mingw*]:
	Fix support for posix threading on aarch64 mingw targets.

Signed-off-by: Timo Rothenpieler <timo@rothenpieler.org>
2 files changed