testsuite, rs6000: Remove powerpc_popcntb_ok
There are three uses of effective target powerpc_popcntb_ok,
they are all for compiling, but powerpc_popcntb_ok checks
for executable generation, which is too heavy. This patch
is to remove powerpc_popcntb_ok and adjust its three uses
accordingly.
gcc/testsuite/ChangeLog:
* lib/target-supports.exp (check_effective_target_powerpc_popcntb_ok):
Remove.
* gcc.target/powerpc/cmpb-2.c: Adjust with dg-skip-if as
powerpc_popcntb_ok gets removed.
* gcc.target/powerpc/cmpb-3.c: Likewise.
* gcc.target/powerpc/cmpb32-2.c: Likewise.