[llvm] [Support][Memory] Add memfd based fallback for strict W^X Linux systems (PR #98538)

[via llvm-commits]

minipli-oss wrote:

I did a review and fixes myself and added them to the branch as follol-up commits, to ease review. My plan is to squash these into the first commit for a merge, though.

The changes fix error handling for old systems as well as supporting recent kernels better. I also added an explicit test for the W->X memory transition which is now supported through this change.

https://github.com/llvm/llvm-project/pull/98538