[PATCH] Add valgrind smoke test

[Joseph Myers]

I'm seeing

FAIL: elf/tst-valgrind-smoke

for the x86_64 configurations when running build-many-glibcs.py (and 
UNSUPPORTED for other architectures).  No execution tests of the newly 
built glibc should be run at all unless

ifeq ($(run-built-tests),yes)

but I don't see any such conditional around the

tests-special += $(objpfx)tst-valgrind-smoke.out

that causes this test to be run.

-- 
Joseph S. Myers
joseph@codesourcery.com