test-lib: have SANITIZE=leak imply TEST_NO_MALLOC_CHECK

Since 131b94a (test-lib.sh: Use GLIBC_TUNABLES instead of
MALLOC_CHECK_ on glibc >= 2.34, 2022-03-04) compiling with
SANITIZE=leak has missed reporting some leaks. The old MALLOC_CHECK
method used before glibc 2.34 seems to have been (mostly?) compatible
with it, but after 131b94a e.g. running:

	TEST_NO_MALLOC_CHECK=1 make SANITIZE=leak test T=t6437-submodule-merge.sh

Would report a leak in builtin/commit.c, but this would not:

	TEST_NO_MALLOC_CHECK= make SANITIZE=leak test T=t6437-submodule-merge.sh

Since the interaction is clearly breaking the SANITIZE=leak mode,
let's mark them as explicitly incompatible.

A related regression for SANITIZE=address was fixed in
067109a (tests: make SANITIZE=address imply TEST_NO_MALLOC_CHECK,
2022-04-09).

Signed-off-by: Ævar Arnfjörð Bjarmason <[email protected]>
Acked-by: Phillip Wood <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: avar

t/test-lib.sh

@@ -545,9 +545,11 @@ case $GIT_TEST_FSYNC in
 esac
 
 # Add libc MALLOC and MALLOC_PERTURB test only if we are not executing
-# the test with valgrind and have not compiled with SANITIZE=address.
+# the test with valgrind and have not compiled with conflict SANITIZE
+# options.
 if test -n "$valgrind" ||
    test -n "$SANITIZE_ADDRESS" ||
+   test -n "$SANITIZE_LEAK" ||
    test -n "$TEST_NO_MALLOC_CHECK"
 then
 	setup_malloc_check () {