[all-commits] [llvm/llvm-project] 4c4761: [SDAG] fold extract_vector_elt with undef index

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  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 4c47617627fbc88fe91195528408178b2dc0e4c9
      https://github.com/llvm/llvm-project/commit/4c47617627fbc88fe91195528408178b2dc0e4c9
  Author: Sanjay Patel <spatel at rotateright.com>
  Date:   2019-10-25 (Fri, 25 Oct 2019)

  Changed paths:
    M llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
    M llvm/test/CodeGen/AMDGPU/indirect-addressing-si-noopt.ll
    M llvm/test/CodeGen/WebAssembly/simd.ll
    M llvm/test/CodeGen/X86/extractelement-index.ll

  Log Message:
  -----------
  [SDAG] fold extract_vector_elt with undef index

This makes the DAG behavior consistent with IR's extractelement after:
rGb32e4664a715

https://bugs.llvm.org/show_bug.cgi?id=42689

I've tried to maintain test intent for WebAssembly.
The AMDGPU test is trying to test for crashing or other bad behavior,
but I'm not sure if that's possible after this change.