[RISCV][GISel] Split LoadStoreActions in LoadActions and StoreActions.
Remove widenToNextPow2 from StoreActions.
Reorder clampScalar and lowerIfMemSizeNotByteSizePow2 for StoreActions.
These match AArch64 and got me further on a test case I was playing with
that contained a i129 store.
llvm-project
1e9d0028 - [RISCV][GISel] Split LoadStoreActions in LoadActions and StoreActions.
