[compiler-rt] Reapply [compiler-rt] prctl interception update, SECCOMP_MODE_FILTER … (PR #109834)

[David CARLIER via llvm-commits]

devnexen wrote:

I guess [this part](https://github.com/llvm/llvm-project/pull/109834/files#diff-d8dd05a3dee58959cd023ef105f48682730702fa0aa24032e5a4fc5500b36d4eR535) needs to be made available for musl too.

https://github.com/llvm/llvm-project/pull/109834