[PATCH] Fix PR c++/14755

[Gabriel Dos Reis]

Mark Mitchell <mark@codesourcery.com> writes:

| Jakub Jelinek wrote:
| 
| >Hi!
| >
| > This bug marked as critical has been introduced by the 2004-03-08
| > Roger Sayle  <roger@eyesopen.com>
| >
| >        * fold-const.c (fold) <EQ_EXPR>: Rewrite optimization to transform
| >        "foo++ == const" into "++foo == const+incr".
| >The masking is only correct for TREE_UNSIGNED (TREE_TYPE (varop)), otherwise
| >it needs sign extension to the bit fields precision.
| >Fixed thusly, ok to commit if bootstrap/regression testing succeeds?
| >Ok for 3.4/3.3 as well?
| >
| OK.  Thanks!

Same for 3.3.4.