Policy for removing target support

[Nick Clifton]

Hi Guys,

>> * Remove support for Solaris < 10 immediately.
>>
>>    Given that all affected targets are long dead, support for them in
>>    GCC has been removed between 10 and 12 years ago and they don't even
>>    build since binutils 2.41, there's little point claiming support if it
>>    doesn't actually work and nobody noticed.
>>
>> * Alternatively, one could obsolete them instead and remove support at a
>>    later point (when?).  That has the disadvantage of leaving the support
>>    in bfd/config.bfd and ld/configure.tgt more complex than necessary and
>>    sort of advertising support for OS versions that don't actually work.

Obsolete first, remove later.

Specifically, set the target string(s) as pending obsolescence by adding them
to the case statement at the start of the config.bfd file - so that they can
only be built by configuring with --enable-obsolete.  Then after the next major
release (ie 2.46), move the string(s) to the completely obsolete list that
follows in the next case statement.  At that point completely removing the code
is fine.

This has been the standard way that we have remove support for various targets
in the past, and I think that it should work here.

If it helps, one of the steps in the README-how-to-make-a-release document
is to explicitly move pending obsolesence targets into the fully obsolescent
list, so whomever makes the 2.46 release should automatically handle the
making-fully-obsolescent step for you.

Cheers
   Nick