config.gcc (*-*-mingw*): Allow as option the posix threading model.

config.gcc (*-*-mingw*): Allow as option the posix threading model.

2011-04-01  Kai Tietz  <ktietz@redhat.com>

	* config.gcc (*-*-mingw*): Allow as option the
	posix threading model.
	* config/i386/mingw32.h ( SPEC_PTHREAD1,  SPEC_PTHREAD2):
	New macros defined dependent to TARGET_USE_PTHREAD_BY_DEFAULT
	definition.
	(CPP_SPEC): Add pthread/no-pthread handling.
	(LIB_SPEC): Likewise.
	* config/i386/mingw-w64.h (CPP_SPEC):Likewise.
	(LIB_SPEC): Likewise.
	* config/i386/t-cygming (SHLIB_PTHREAD_CFLAG): New
	flag to pass -pthread option for shared libgcc build.
	(SHLIB_PTHREAD_LDFLAG): New option to pass -lpthread
	for shared libgcc build.
	* config/i386/t-mingw-pthread: New file.
	* config/i386/mingw-pthread.h (TARGET_USE_PTHREAD_BY_DEFAULT):
	New define to enable use of library pthread by default.
	* config/i386/mingw.opt (pthread): New driver option.
	(no-pthread): New driver option.
	* config/i386/cygming.opt: Make sure trailing empty line
	is retained.
	* config/i386/mingw-w64.opt: Likewise.

From-SVN: r171833