[vta] created 4.3 branch, merged 4.3 and trunk @138264

[Alexandre Oliva <aoliva at redhat dot com>]

I forked the vta branch into a var-tracking-assignments-4_3-branch,
created and merged from gcc-4_3-branch on Wednesday, and I've just
finished merging the trunk onto the var-tracking-assignments-branch.
Both merges were mostly trivial, although the trunk merge required the
tuplification of debug stmts.

I didn't expect difficulties here, but it turned out to be much easier
than I'd anticipated.  I added GIMPLE_DEBUG, with VAR_DEBUG_VALUE as a
subcode, and then, after a few tweaks here and there, it all built.  I
haven't assessed the quality of debug information yet (err, guality),
though.

No patches, but the diffs between the baselines and the post-merge
state can be obtained with commands such as:

# svn diff svn://gcc.gnu.org/svn/gcc/tags/var-tracking-assignments-4_3-merge-138264-{4_3,after}

# svn diff svn://gcc.gnu.org/svn/gcc/tags/var-tracking-assignments-merge-138264-{trunk,after}

The 4.3 branch won't bootstrap without a couple of patches I'm post
and install momentarily; the trunk builds at least all the way to the
end of stage2.  That's all the testing I've done.

The previous state of the branch can be obtained with

svn checkout svn://gcc.gnu.org/svn/gcc/tags/var-tracking-assignments-merge-138264-before

-- 
Alexandre Oliva         http://www.lsd.ic.unicamp.br/~oliva/
Free Software Evangelist  oliva@{lsd.ic.unicamp.br, gnu.org}
FSFLA Board Member       ÂSÃ Libre! => http://www.fsfla.org/
Red Hat Compiler Engineer   aoliva@{redhat.com, gcc.gnu.org}