Pull in r342397 from upstream llvm trunk (by Amara Emerson):
Revert "Revert r342183 "[DAGCombine] Fix crash when store merging created an extract_subvector with invalid index."" Fixed the assertion failure. Differential Revision: https://reviews.llvm.org/D51831
This fixes 'Assertion failed: ((VT.getVectorNumElements() +
N2C->getZExtValue() <= N1.getValueType().getVectorNumElements()) &&
"Extract subvector overflow!"), function getNode' when building the
multimedia/aom port (with AVX2 enabled).
Reported by: jbeich
PR: 234480
MFC after: 6 weeks
X-MFC-With: r341825