[v3] unify 3_4 and 3_5 libstdc++

[Benjamin Kosnik]

This patch set unifies the libstdc++ ABI's across 3.4 and 3.5 trees. It
does not break out bits into small chunks, and includes things like
testsuite layout changes and documentation additions that are not
strictly necessary from an ABI point of view but seem like things that
will help long-term maintenance of the 3.4 tree going forward.

The 3.4 patched sources are mostly similar to 3.5, with the following
exceptions:

1) The autotools versions are unchanged from current 3.4 source
requirements

2) Known reversions for gcc-3_4-branch are intact. A small part of one
of Paolo's patches is reverted, due to build errors. 

3) The dg-require-iconv bits, which are not working on 3.5 branch, are
not applied to the 3.4 branch.

The testresults from the current gcc-3_4-branch sources, with this patch
applied, are  fine on the two targets I have built: x86 linux (FC1) and
powerpc darwin (10.3). I'd like to have feedback on the following
additional targets:

sparc-solaris2.[7,8,9]
hppa*-hpux
mips-irix6.5+
powerpc-aix5

Extrapolating from the current 3.5.0 testresults for each of these
targets, I conclude that this patch would have a minimal impact on test
results for the above targets. However, it might be wise to wait for
confirmation of this hypothesis.

Pre-patches libstdc++ sources, which are current
gcc-3_4-branch/libstdc++-v3 + this patch are located here:

http://people.redhat.com/bkoz/libstdc++-v3.merged.tar.bz2

The patch itself is here:
http://people.redhat.com/bkoz/p.20040315-merge.bz2

-benjamin

tested x86/linux

pre
                                                                               
XPASS: 26_numerics/c99_classification_macros_c.cc (test for excess errors)
 
                === libstdc++ Summary ===
  
# of expected passes            2573
# of unexpected successes       1
# of expected failures          5

post


XPASS: 26_numerics/c99_classification_macros_c.cc (test for excess errors)
FAIL: thread/pthread7-rope.cc execution test
  
                === libstdc++ Summary ===
  
# of expected passes            2628
# of unexpected failures        1
# of unexpected successes       1
# of expected failures          5


tested powerpc-apple-darwin7.2.0

pre

                === libstdc++ Summary ===
 
# of expected passes            2571
# of unexpected failures        3
# of expected failures          5


post

FAIL: 27_io/basic_filebuf/open/char/9507.cc execution test
FAIL: 27_io/ios_base/storage/11584.cc execution test
 
                === libstdc++ Summary ===
 
# of expected passes            2628
# of unexpected failures        2
# of expected failures          5