RFC: [PATCH] Support -plugin-opt=disable-output for LLVM plugin

[Rafael Espíndola]

> You can use atexit.  It is used elsewhere in llvm.

The plugin needs an early exit, not a way to schedule stuff to run at exit.

> 1. It expects gold:
>
>     ld_version = subprocess.Popen(['ld', '--version'], stdout = subprocess.PIPE)
>     if not 'GNU gold' in ld_version.stdout.read():
>         return False

This should be fixed to be more general.

> 2. It expects elf32ppc support:
>
>   emulations = fields[2].split()
>     if 'elf32ppc' not in emulations or 'elf_x86_64' not in emulations:
>         return False
>
> Even my gold doesn't have elf32ppc support.

This should be moved to a ppc specific subdirectory.

Cheers,
Rafael