[PATCH] Fix PR77286

[Dominique d'Humières]

This patch causes:

FAIL: gfortran.dg/vect/pr69466.f90   -O  (internal compiler error)
FAIL: gfortran.dg/vect/pr69466.f90   -O  (test for excess errors)
with -m32.

[Book15] f90/bug% gfc /opt/gcc/_clean/gcc/testsuite/gfortran.dg/vect/pr69466.f90 -O2 -ftree-vectorize -m32 -march=core-avx2
/opt/gcc/_clean/gcc/testsuite/gfortran.dg/vect/pr69466.f90:4:0:

  subroutine foo
 
internal compiler error: in slpeel_duplicate_current_defs_from_edges, at tree-vect-loop-manip.c:750

TIA

Dominique