[llvm-branch-commits] [llvm] release/18.x: [AArc64][GlobalISel] Fix legalizer assert for G_INSERT_VECTOR_ELT - manual merge (PR #91672)

[Amara Emerson via llvm-branch-commits]

aemerson wrote:

Test has been changed from original commit due to a fallback in a G_BITCAST. Added abort=2 so we can see partial legalization and check no crash.

https://github.com/llvm/llvm-project/pull/91672