Changes

Summary

[AArch64] Fix -Wunused-but-set-variable in GCC -DLLVM_ENABLE_ASSERTIONS=off build (details)
[X86][AVX] Handle vperm2x128 shuffling of a subvector splat. (details)
[RISCV] Remove unnecessary APInt copy. NFC (details)

Commit 36e62b1ff7e7aa883f8ea2f236e9c04df6976b59 by i [AArch64] Fix -Wunused-but-set-variable in GCC -DLLVM_ENABLE_ASSERTIONS=off build
	llvm/lib/Target/AArch64/GISel/AArch64InstructionSelector.cpp
Commit b8b5e87e6b8102d77e4e6beccf4e0f0237acc897 by llvm-dev [X86][AVX] Handle vperm2x128 shuffling of a subvector splat. We already handle "vperm2x128 (ins ?, X, C1), (ins ?, X, C1), 0x31" for shuffling of the upper subvectors, but we weren't dealing with the case when we were splatting the upper subvector from a single source.
	llvm/test/CodeGen/X86/avx-vperm2x128.ll
	llvm/lib/Target/X86/X86ISelLowering.cpp
	llvm/test/CodeGen/X86/vector-shuffle-256-v8.ll
Commit 9d792fef577843b213aa11954820512942dc31c7 by craig.topper [RISCV] Remove unnecessary APInt copy. NFC getAPIntValue returns a const APInt& so keep it as a reference.
	llvm/lib/Target/RISCV/RISCVISelLowering.cpp