Implement x86 pause intrinsic.

Implement x86 pause intrinsic.

gcc/

2011-05-25  H.J. Lu  <hongjiu.lu@intel.com>

	* config/i386/i386.c (ix86_builtins): Add IX86_BUILTIN_PAUSE.
	(bdesc_special_args): Add pause intrinsic.

	* config/i386/i386.md (UNSPEC_PAUSE): New.
	(pause): Likewise.
	(*pause): Likewise.
	* config/i386/ia32intrin.h (__pause): Likewise.

	* doc/extend.texi (X86 Built-in Functions): Add documentation for
	pause intrinsic.

gcc/testsuite/

2011-05-25  H.J. Lu  <hongjiu.lu@intel.com>

	 * gcc.target/i386/pause-1.c: New.

From-SVN: r174197