Normalize backend's elf structures with system headers.
Forward to system headers when available.
[Refactoring] Remove duplication of nothrow check code
fix Issue 13504 - ICE(backend/cgelem.c 2418) with "-O -cov"

- assert failed because goal wasn't properly passed down
Merge pull request #4046 from 9rnsr/refactor_func

[Refactoring] Remove duplication of nothrow check code
Merge pull request #4047 from MartinNowak/fix13504

fix Issue 13504 - ICE(backend/cgelem.c 2418) with "-O -cov"
Merge pull request #3814 from yebblies/crazyelf

[cleanup] Normalize backend's elf structures with system headers.