re PR target/51244 ([SH] Inefficient conditional branch and code around T bit)

	PR target/51244
	* config/sh/sh.md (negsi_cond, negdi_cond, stack_protect_test): Remove
	get_t_reg_rtx when invoking gen_branch_true or gen_branch_false.
	(*zero_extend<mode>si2_compact): Convert to insn_and_split.  Convert
	zero extensions of T bit stores to reg moves in splitter.  Remove
	obsolete unnamed peephole2 that caught zero extensions after negc T bit
	stores.
	(*branch_true_eq, *branch_false_ne): Delete.
	(branch_true, branch_false): Convert insn to expander.  Move actual
	insn logic to...
	(*cbranch_t): ...this new insn_and_split.  Try to find preceding
	redundant T bit stores and tests and combine them with the conditional
	branch if possible in the splitter.
	(movrt_xor, *movt_movrt): New insn_and_split.
	* config/sh/predicates.md (cbranch_treg_value): New predicate.
	* config/sh/sh-protos.h (sh_eval_treg_value): Forward declare...
	* config/sh/sh.c (sh_eval_treg_value): ...this new function.
	(expand_cbranchsi4, expand_cbranchdi4): Remove get_t_reg_rtx
	when invoking gen_branch_true or gen_branch_false.

	PR target/51244
	* gcc.target/sh/pr51244-13.c: New.
	* gcc.target/sh/pr51244-14.c: New.
	* gcc.target/sh/pr51244-15.c: New.
	* gcc.target/sh/pr51244-16.c: New.

From-SVN: r192387