re PR target/55301 ([SH] broken sp_switch function attribute)

re PR target/55301 ([SH] broken sp_switch function attribute)

PR target/55301
* config/sh/sh.c (sh_expand_prologue): Postpone new_stack mem symbol.
(broken_move): Handle UNSPECV_SP_SWITCH_B.
* config/sh/sh.md (sp_switch_1): Use set (reg:SI SP_REG).

* config/sh/sh.md (UNSPECV_SP_SWITCH_B): New.
(UNSPECV_SP_SWITCH_E): New.
(sp_switch_1): Change to an unspec.
(sp_switch_2): Change to an unspec.  Don't use post-inc when we
replace $r15.

* gcc.target/sh/sh-switch.c: New testcase.

From-SVN: r195230