LEON now uses the standard V8 membar patterns that contains an ldstub
instruction. This instruction needs to be aligned properly when the
GR712RC errata workaround is enabled.
gcc/ChangeLog:
* config/sparc/sparc.cc (atomic_insn_for_leon3_p): Treat membar_storeload as atomic
* config/sparc/sync.md (membar_storeload): Turn into named insn
and add GR712RC errata workaround.
(membar_v8): Add GR712RC errata workaround.