phiopt: Optimize x ? __builtin_clz (x) : 32 in GIMPLE fallout [PR97503]

phiopt: Optimize x ? __builtin_clz (x) : 32 in GIMPLE fallout [PR97503]

> this broke sparc-sun-solaris2.11 bootstrap
>
> /vol/gcc/src/hg/master/local/gcc/tree-ssa-phiopt.c: In function 'bool cond_removal_in_popcount_clz_ctz_pattern(basic_block, basic_block, edge, edge, gimple*, tree, tree)':
> /vol/gcc/src/hg/master/local/gcc/tree-ssa-phiopt.c:1858:27: error: variable 'mode' set but not used [-Werror=unused-but-set-variable]
>  1858 |           scalar_int_mode mode = SCALAR_INT_TYPE_MODE (TREE_TYPE (arg));
>       |                           ^~~~
>
>
> and doubtlessly several other targets that use the defaults.h definition of
>
> #define CTZ_DEFINED_VALUE_AT_ZERO(MODE, VALUE)  0

Ugh, seems many of those macros do not evaluate the first argument.
This got broken by the change to direct_internal_fn_supported_p, previously
it used mode also in the optab test.

2020-10-22  Jakub Jelinek  <jakub@redhat.com>

	* tree-ssa-phiopt.c (cond_removal_in_popcount_clz_ctz_pattern):
	For CLZ and CTZ tests, use type temporary instead of mode.