[SH][committed] Add tst insn test cases

[Oleg Endo]

Hi,

This adds some more SH tst insn test cases.  Most of them are currently
failing and thus are marked as xfail.  I'm working on some patches for
those cases.
Tested with
make -k check-gcc RUNTESTFLAGS="sh.exp=pr49263* --target_board=sh-sim
\{-m2/-ml,-m2/-mb,-m2a/-mb,-m4/-ml,-m4/-mb,-m4a/-ml,-m4a/-mb}"
Committed as r219111.

Cheers,
Oleg

gcc/testsuite/ChangeLog:
        PR target/49263
        * gcc.target/sh/pr49263-1.c: New.
        * gcc.target/sh/pr49263-2.c: New.