[Bug other/63504] [5 Regression] Issues found by --enable-checking=valgrind

["trippels at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63504

--- Comment #4 from Markus Trippelsdorf <trippels at gcc dot gnu.org> ---
On x86_64-unknown-linux-gnu everything seems fine, 
but issues 1) and 3) can be reproduced with a cross:

../gcc/configure --target=powerpc64-unknown-linux-gnu --disable-libsanitizer
--disable-bootstrap --disable-libstdcxx-pch --disable-libvtv --disable-libitm
--disable-libcilkrts --disable-libssp --disable-libgomp --disable-werror
--disable-multilib --enable-languages=c,c++,fortran

1)
valgrind --track-origins=yes --trace-children=yes ./gcc/xgcc -Bgcc -std=gnu11
-fcx-fortran-rules -g -O2 -S ~/maxloc0_4_i16.i

2)
Happened during testsuite run on a 64-core machine. So it is hard to tell
which command line triggered the problem. And running the testsuite single-
threaded would take weeks.

3)
valgrind --track-origins=yes --trace-children=yes ./gcc/gfortran -Bgcc
~/gcc/gcc/testsuite/gfortran.dg/actual_array_result_1.f90 -S
-fno-diagnostics-show-caret -fdiagnostics-color=never -Os -c