Auto merge of #105384 - uweigand:s390x-test-codegen, r=Mark-Simulacrum

Fix failing codegen tests on s390x

Several codegen tests are currently failing due to making assumptions that are not valid for the s390x architecture:

- catch-unwind.rs: fails due to inlining differences. Already ignored on another platform for the same reason. Solution: Ignore on s390x.

- remap_path_prefix/main.rs: fails due to different alignment requirement for string constants. Solution: Do not test for the alignment requirement.

- repr-transparent-aggregates-1.rs: many ABI assumptions. Already ignored on many platforms for the same reason. Solution: Ignore on s390x.

- repr-transparent.rs: no vector ABI by default on s390x. Already ignored on another platform for a similar reason. Solution: Ignore on s390x.

- uninit-consts.rs: hard-coded little-endian constant. Solution: Match both little- and big-endian versions.

Fixes part of https://github.com/rust-lang/rust/issues/105383.