gcc: another round of merges from the gcc pre-43 branch.

gcc: another round of merges from the gcc pre-43 branch.

Bring The following revisions from the gcc43 branch[1]:

118360, 118361, 118363, 118576, 119820,
123906, 125246, and 125721.

They all have in common that the were merged long ago
into Apple's gcc and should help improve the general
quality of the compiler and make it easier to bring
new features from Apple's gcc42.

For details please review the additions to the files:
gcc/ChangeLog.gcc43
gcc/cp/ChangeLog.gcc43 (new, adds previous revisions)

Reference:
[1] http://gcc.gnu.org/viewcvs/gcc/trunk/?pathrev=126700

Obtained from:	gcc pre4.3 (GPLv2) branch
MFC after:	3 weeks