[Bug tree-optimization/51491] ccp when converting from alloca should add a CLOBBER to right before __builtin_stack_restore

[vries at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51491

vries at gcc dot gnu.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |rguenther at suse dot de,
                   |                            |vries at gcc dot gnu.org

--- Comment #2 from vries at gcc dot gnu.org 2011-12-12 13:12:16 UTC ---
I ran:
...
$ ./install/bin/mips64el-linux-gnu-gcc $src -O3 -g -march=octeon 
-fdump-tree-all -msoft-float
...

for:
- src/gcc-mainline/gcc/testsuite/gcc.c-torture/execute/20040811-1.c
- src/gcc-mainline/gcc/testsuite/gcc.c-torture/execute/vla-dealloc-1.c.

In both cases an alloca_with_align is generated during gimplify from a vla,
which still exists at expand, and ccp leaves the alloca_with_align alone.  So
I'm not sure what I should fix in ccp.