Fix ICE from reg-stack->fixup_abnormal_edges

[Olivier Hainque]

Eric Botcazou wrote:
> Looks very similar to PR opt/9786 which is targeted to 3.3.1 and has a C++ 
> testcase.

 Exactly the same issue, indeed. Thanks for the prompt feedback.

 The suggested patch fixes it also:

Using untouched yesterday's mainline sources:

$ ./gcc-3.4/_FOR_REFERENCE/bld/gcc/cc1plus -O2 -fnon-call-exceptions foo.C
foo.C:20: internal compiler error: in fixup_abnormal_edges, at reload1.c:7985
Please submit a full bug report,

With the patch applied:

$ ./gcc-3.4/_FOR_PATCH/bld/gcc/cc1plus -O2 -fnon-call-exceptions foo.C
[...]
Execution times (seconds)
 parser                :   0.03 (75%) usr   0.00 ( 0%) sys   0.04 ( 9%) wall
[...]