PowerPC:, Update test test_isa_3_1_R1_RT.c, test_isa_3_1_R1_XT.c

PowerPC:, Update test test_isa_3_1_R1_RT.c, test_isa_3_1_R1_XT.c

The commit:

  commit 20cc0680c3491e062c76605b24e76dc02e16ef47
  Author: Carl Love <cel@us.ibm.com>
  Date:   Mon Apr 17 17:12:25 2023 -0400

      PowerPC:, Fix test test_isa_3_1_R1_RT.c, test_isa_3_1_R1_XT.c

Fixes an issue with the PAD_ORI used in the the tests by explicitly adding
SAVE_REGS and RESTORE_REGS macros.  The macros ensure that the block of
immediate OR instructions don't inadvertently change the contents of the
registers.

John Reiser suggested that the PAD_ORI asm statements in the PAD_ORI
macro be updated to inform the compiler which register the ori instruction
is clobbering.  The compiler will then generate the code to save and
restore the register automatically.  This is a cleaner solution then
explicitly adding the macros to store and restore the registers.  It is
functionally cleaner in that the value fetched by the instruction under
test is not modified by the PAD_ORI instructions.

This patch removes the SAVE_REG and RESTORE_REG macros and updates the
PAD_ORI macro.