[Bug middle-end/67442] [5/6 Regression] GCC 5.2.0 on x86_64 creates invalid address on specific array index calculation through pointer

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67442

--- Comment #10 from Richard Biener <rguenth at gcc dot gnu.org> ---
Assert triggers through

/space/rguenther/src/svn/trunk2/gcc/testsuite/g++.dg/tree-ssa/pr49911.C:8:22:
internal compiler error: in wide_int_to_tree, at tree.c:1398^M
0xf49a69 wide_int_to_tree(tree_node*,
generic_wide_int<wide_int_ref_storage<false> > const&)^M
        /space/rguenther/src/svn/trunk2/gcc/tree.c:1398^M
0xcab4e4 set_min_and_max_values_for_integral_type(tree_node*, int, signop)^M
        /space/rguenther/src/svn/trunk2/gcc/stor-layout.c:2645^M
0x62c701 finish_enum_value_list(tree_node*)^M
        /space/rguenther/src/svn/trunk2/gcc/cp/decl.c:13267^M

-fstrict-enums related.  set_min_and_max_values_for_integral_type
doesn't handle differing sgn correctly.