Backport 9067070d91e9d8cdd8509ffa56a076f08a3d7281 to release/18.x

[topperc]

This splits the unaligned scalar and vector controls in the backend. This will allow the -Xclang -target-feature -Xclang +unaligned-scalar-mem option that used to work on llvm 17 to work again.

We need to work within the RISC-V community to figure out how -mno-strict-align should behave.

Related issue #88029

[llvmbot]

@llvm/issue-subscribers-backend-risc-v

Author: Craig Topper (topperc)

This splits the unaligned scalar and vector controls in the backend. This will allow the `-Xclang -target-feature -Xclang +unaligned-scalar-mem` option that used to work on llvm 17 to work again.

We need to work within the RISC-V community to figure out how -mno-strict-align should behave.

Related issue #88029

[topperc]

/cherry-pick 9067070

[llvmbot]

Failed to cherry-pick: 9067070

https://github.com/llvm/llvm-project/actions/runs/9082269777

Please manually backport the fix and push it to your github fork. Once this is done, please create a pull request