hotfix: make ifx work with autoconf <= 2.69 in Spack (#22683)

Autoconf before 2.70 will erroneously pass ifx's -loopopt argument to the
linker, requiring all packages to use autoconf 2.70 or newer to use ifx.

This is a hotfix enabling ifx to be used in Spack. Instead of bothering
to upgrade autoconf for every package, we'll just strip out the
problematic flag if we're in `ld` mode.

- [x] Add a conditional to the `cc` wrapper to skip `-loopopt` in `ld`
      mode. This can probably be generalized in the future to strip more
      things (e.g., via an environment variable we can constrol from
      Spack) but it's good enough for now.

- [x] Add a test ensuring that `-loopopt` arguments are stripped in link
      mode, but not in compile mode.

0 files changed, 0 insertions, 0 deletions