Fixes#43494
Add a set of environment variables SPACK_ALWAYS_CFLAGS (etc.) that
are always applied by the compiler wrapper.
Unlike SPACK_CFLAGS, for example, these will also be applied to
version checks (both SPACK_CFLAGS and SPACK_ALWAYS_CFLAGS will be
applied to the other invocation modes like ccld etc.).
Using this new functionality, the classic Intel and oneAPI compilers
are updated to pass compiler flags that disable warning messages
when newer versions are invoked via their older binary names
(these warnings were also generated for version checks, hence the
need for a new wrapper variable).
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Co-authored-by: Peter Josef Scheibel <scheibel1@llnl.gov>
0902910784