Add new options: -mext-perf, -mext-perf2, -mext-string.
gcc/
* config/nds32/nds32.opt: Add mext-perf, mext-perf2, mext-string.
* config/nds32/nds32.opt: Refine the layout.
* config/nds32/nds32.c (TARGET_EXT_PERF, TARGET_EXT_PERF2,
TARGET_EXT_STRING): Support new options.
* config/nds32/nds32.h: Likewise.
* config/nds32/nds32.md: Likewise.
* config/nds32/nds32-predicates.c: Likewise.
* config/nds32/constraints.md: Likewise.
* common/config/nds32/nds32-common.c: Likewise.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@254798 138bc75d-0d04-0410-961f-82ee72b054a4