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
yl2x asm, remove finit and fwait
Merge pull request #4052 from IgorStepanov/yl2x-fix

yl2x asm, remove finit and fwait
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.
fix Issue 11355 - Copy through alias this with @disabled this(this)
Merge pull request #4054 from 9rnsr/fix11355

Issue 11355 - Copy through alias this with @disabled this(this)
C-style function pointers now an error
Merge pull request #4056 from WalterBright/error-fp

C-style function pointers now an error