sourcebuild.texi (Effective-Target Keywords, [...]): Document mmap.

sourcebuild.texi (Effective-Target Keywords, [...]): Document mmap.

	gcc:
	* doc/sourcebuild.texi (Effective-Target Keywords, Environment
	attributes): Document mmap.

	gcc/testsuite:
	* lib/target-supports.exp (check_effective_target_mmap): New proc.

	* gcc.c-torture/execute/loop-2f.c: Remove #ifdef __unix__.
	* gcc.c-torture/execute/loop-2g.c: Likewise.
	* gcc.c-torture/execute/loop-2f.x: Load target-supports.exp.
	Require mmap support.
	* gcc.c-torture/execute/loop-2g.x: Likewise.
	* gcc.dg/20030711-1.c: Replace dg-do target list by mmap.
	(MAP_ANON): Provide default.
	* gcc.dg/20050826-1.c: Likewise.
	* gcc.target/i386/pr36533.c: Likewise.
	* gcc.dg/vect/pr49038.c: Remove dg-do run.
	Use dg-require-effective-target mmap.

From-SVN: r176760