* configure.ac: Skip check for i686-w64-mingw32-g++ on x86_64.
* configure: Regenerate.
	* cygwin.din (_get_osfhandle): Make main export.  Define get_osfhandle
	from here.
	* cygwin64.din (_get_osfhandle): Rename from get_osfhandle.
	(_setmode): Rename from setmode.
	* include/io.h: Ditto. Define unprefixed names with preprocessor
	macros for backwards source compatibility.
	(access): Remove.
	* syscalls.cc (_setmode): Rename from setmode.
	(cygwin_setmode): Call _setmode.
	(_get_osfhandle): Rename from get_osfhandle.
Merge branch 'cygwin64' into msys2-64-dev