Merge MIPS libc-abis into top-level

[Joseph S. Myers]

On Wed, 1 Oct 2014, Matthew Fortune wrote:

> This patch merges the MIPS specific libc-abis file into the top
> level. MIPS is the only port with a custom file while there are
> several conditional entries in the top level file already. I
> suspect the only reason we have the custom file is because of
> MIPS coming from the ports tree. Now that ports are gone this
> is no longer an issue.

But the direction we are following is that the way ports architectures did 
things is generally the preferred direction and non-ex-ports architectures 
should follow it - that is, avoid anything architecture-specific in 
architecture-independent files, with sysdeps directories used for all 
selection of anything architecture-specific.  So it would seem better to 
work out a design that moves architecture-specific content out of the 
toplevel file, and eliminates the special-case matching against 
$(base-machine)-$(config-vendor)-$(config-os) with normal sysdeps 
searching being used instead, while still avoiding duplication between 
architectures as much as possible.

See also the discussion in 
<https://sourceware.org/ml/libc-alpha/2014-01/msg00375.html> and the 
references therefrom.  I think a more careful analysis of libc-abis issues 
would be needed to justify any particular patch merging or splitting 
files.

-- 
Joseph S. Myers
joseph@codesourcery.com