[SystemZ] Fix truncstore + bswap codegen bug
SystemZTargetLowering::combineSTORE contains code to transform a
combination of STORE + BSWAP into a STRV type instruction.
This transformation is correct for regular stores, but not for
truncating stores. The routine neglected to check for that case.
Fixes a miscompilation of llvm-objcopy with clang, which caused
test suite failures in the SystemZ multistage build bot.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@313669
91177308-0d34-0410-b5e6-
96231b3b80d8