help wanted from Alpha maintainers: -mieee

[Nathanael Nerode <neroden at doctormoo dot dyndns dot org>]

Currently there's some very funky behavior going on.  "-mieee" is added
to CFLAGS_FOR_TARGET and CXXFLAGS_FOR_TARGET (for Alpha targets) in the
top level Makefile.  It's added by a top level Makefile fragment which
uses the += notation and therefore isn't totally portable.  Furthermore,
it seems to be added all the time regardless of flags passed by the
user.

I'm not sure what's going on here, but I don't like it.

Obviously this flag is only meaningful to gcc.  Accordingly, it seems
like the logical behavior is one of the following, depending on what
the purpose of this is:
* gcc with target alpha *defaults* to the -mieee status, and it has to
be turned *off* with a flag
* each target library or target program which wants -mieee requests it
independently

Commentary from some Alpha maintainers might help me unravel this;
ideally I'd like to be able to wipe out "config/mt-alphaieee" entirely.

Thanks,
--Nathanael Nerode