sourcebuild.texi: Document dg-add-options mips16_attribute.

sourcebuild.texi: Document dg-add-options mips16_attribute.

gcc/
	* doc/sourcebuild.texi: Document dg-add-options mips16_attribute.

gcc/testsuite/
	* lib/target-supports.exp (add_options_for_mips16_attribute)
	(check_effective_target_mips16_attribute): New functions.
	* gcc.target/mips/mips.exp: Define MIPS16 and NOMIPS16 on the
	command line.
	(dg-mips-options) Remove -mno-mips16 handling.  Add options to
	extra_test_flags.
	* gcc.target/mips/asm-1.c (NOMIPS16): Delete.
	* gcc.target/mips/atomic-memory-1.c (NOMIPS16): Likewise.
	* gcc.target/mips/atomic-memory-2.c (NOMIPS16): Likewise.
	* gcc.target/mips/branch-1.c (NOMIPS16): Likewise.
	* gcc.target/mips/dspr2-MULT.c (NOMIPS16): Likewise.
	* gcc.target/mips/dspr2-MULTU.c (NOMIPS16): Likewise.
	* gcc.target/mips/fpcmp-1.c (NOMIPS16): Likewise.
	* gcc.target/mips/fpcmp-2.c (NOMIPS16): Likewise.
	* gcc.target/mips/ins-1.c (NOMIPS16): Likewise.
	* gcc.target/mips/madd-3.c (NOMIPS16): Likewise.
	* gcc.target/mips/maddu-3.c (NOMIPS16): Likewise.
	* gcc.target/mips/mips32-dsp-run.c (NOMIPS16): Likewise.
	* gcc.target/mips/mips32-dspr2-type.c (NOMIPS16): Likewise.
	* gcc.target/mips/msub-3.c (NOMIPS16): Likewise.
	* gcc.target/mips/msubu-3.c (NOMIPS16): Likewise.
	* gcc.target/mips/near-far-3.c (NOMIPS16): Likewise.
	* gcc.target/mips/near-far-4.c (NOMIPS16): Likewise.
	* gcc.target/mips/neg-abs-1.c (NOMIPS16): Likewise.
	* gcc.target/mips/smartmips-lwxs.c (NOMIPS16): Likewise.
	* gcc.target/mips/smartmips-ror-1.c (NOMIPS16): Likewise.
	* gcc.target/mips/smartmips-ror-2.c (NOMIPS16): Likewise.
	* gcc.target/mips/smartmips-ror-3.c (NOMIPS16): Likewise.
	* gcc.target/mips/smartmips-ror-4.c (NOMIPS16): Likewise.
	* gcc.target/mips/pr26765.c: Use dg-mips-options instead of dg-options.
	(NOMIPS16): Delete.
	* gcc.target/mips/20020620-1.c: Use dg-mips-options instead
	of dg-options.
	* gcc.target/mips/call-saved-1.c: Remove -mips16 and -mno-abicalls
	options.  Require { target mips16_attribute } and use dg-add-options
	to add the associated options.
	(foo): Use MIPS16.
	* gcc.target/mips/call-saved-2.c: As for call-saved-1.c.
	* gcc.target/mips/call-saved-3.c: Likewise.
	* gcc.target/mips/code-readable-1.c: Require { target
	mips16_attribute } and use dg-add-options to add the associated
	options.  Remove trailing whitespace.
	(NOMIPS16): Delete.
	* gcc.target/mips/code-readable-2.c: Likewise.
	* gcc.target/mips/code-readable-3.c: Likewise.
	* gcc.target/mips/mips16-attributes-2.c: Likewise.
	* gcc.target/mips/mips16e-extends.c: Remove -mips16 option.
	Require { target mips16_attribute } and use dg-add-options to
	add the associated options.
	(cksum16, cksum8): Use MIPS16.
	* gcc.target/mips/save-restore-1.c: Remove -mips16 option.
	Require { target mips16_attribute } and use dg-add-options to
	add the associated options.
	(foo): Use MIPS16.
	* gcc.target/mips/save-restore-2.c: Likewise.
	* gcc.target/mips/save-restore-3.c: Likewise.
	* gcc.target/mips/save-restore-4.c: Likewise.
	* gcc.target/mips/save-restore-5.c: Likewise.  Also remove
	-mno-abicalls.
	* gcc.target/mips/mips-sched-madd.c: Remove -mno-mips16.
	(foo): Use NOMIPS16.

From-SVN: r128674