xtensa: Turn on -fsplit-wide-types-early by default
Since GCC10, the "subreg2" optimization pass was no longer tied to enabling
"subreg1" unless -fsplit-wide-types-early was turned on (PR88233). However
on the Xtensa port, the lack of "subreg2" can degrade the quality of the
output code, especially for those that produce many D[FC]mode pseudos.
This patch turns on -fsplit-wide-types-early by default in order to restore
the previous behavior.
gcc/ChangeLog:
* common/config/xtensa/xtensa-common.cc
(xtensa_option_optimization_table): Add OPT_fsplit_wide_types_early
for OPT_LEVELS_ALL in order to restore pre-GCC10 behavior.