[NDS32] Add intrinsic functions for atomic load/store and memory sync.
gcc/
* config/nds32/constants.md (unspec_element, unspec_volatile_element):
Add enum values for atomic load/store and memory sync.
* config/nds32/nds32-intrinsic.c: Implementation for atomic load/store
and memory sync.
* config/nds32/nds32-intrinsic.md: Likewise.
* config/nds32/nds32_intrinsic.h: Likewise.
* config/nds32/nds32.h (nds32_builtins): Likewise.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@259207 138bc75d-0d04-0410-961f-82ee72b054a4