[Bug rtl-optimization/59890] var-tracking.c:val_reset segfaults

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59890

--- Comment #5 from Richard Biener <rguenth at gcc dot gnu.org> ---
Seems to break bootstrap now (with -maccumulate-outgoing-args change now for
i?86)
during libquadmath build where

/abuild/rguenther/obj/./gcc/xgcc -B/abuild/rguenther/obj/./gcc/
-B/usr/local/x86_64-unknown-linux-gnu/bin/
-B/usr/local/x86_64-unknown-linux-gnu/lib/ -isystem
/usr/local/x86_64-unknown-linux-gnu/include -isystem
/usr/local/x86_64-unknown-linux-gnu/sys-include -m32 -DHAVE_CONFIG_H -I.
-I/space/rguenther/src/svn/trunk/libquadmath -I
/space/rguenther/src/svn/trunk/libquadmath/../include -g -O2 -MT
printf/mul_n.lo -MD -MP -MF printf/.deps/mul_n.Tpo -c
/space/rguenther/src/svn/trunk/libquadmath/printf/mul_n.c -o printf/mul_n.o

doesn't converge anymore in vt_find_locations ().

Thus, reverted for now, testcase coming (to be attached here).