malloc: Turn tst-mallocstate into a non-internal test

compat_symbol_reference no longer needs tests-internal.  Do not build
the test at all for newer targets, so that no spurious UNSUPPORTED
result is generated.  Use compat_symbol_reference for
__malloc_initialize_hook as well, eliminating the need for -rdynamic.

Reviewed-by: DJ Delorie <dj@redhat.com>

malloc/Makefile

@@ -47,7 +47,12 @@ tests-static := \
 	 tst-interpose-static-thread \
 	 tst-malloc-usable-static \
 
-tests-internal := tst-mallocstate tst-scratch_buffer
+# Test for the malloc_set_state symbol removed in glibc 2.25.
+ifeq ($(have-GLIBC_2.24)$(build-shared),yesyes)
+tests += tst-mallocstate
+endif
+
+tests-internal := tst-scratch_buffer
 
 # The dynarray framework is only available inside glibc.
 tests-internal += \
@@ -118,9 +123,6 @@ $(objpfx)tst-malloc-thread-fail-mcheck: $(shared-thread-library)
 $(objpfx)tst-malloc-fork-deadlock-mcheck: $(shared-thread-library)
 $(objpfx)tst-malloc-stats-cancellation-mcheck: $(shared-thread-library)
 
-# Export the __malloc_initialize_hook variable to libc.so.
-LDFLAGS-tst-mallocstate = -rdynamic
-
 # These should be removed by `make clean'.
 extra-objs = mcheck-init.o libmcheck.a
 others-extras = mcheck-init.o

malloc/tst-mallocstate.c

@@ -29,8 +29,6 @@
 
 #include "malloc.h"
 
-#if TEST_COMPAT (libc, GLIBC_2_0, GLIBC_2_25)
-
 /* Make the compatibility symbols availabile to this test case.  */
 void *malloc_get_state (void);
 compat_symbol_reference (libc, malloc_get_state, malloc_get_state, GLIBC_2_0);
@@ -310,6 +308,8 @@ init_heap (void)
 
 /* Interpose the initialization callback.  */
 void (*volatile __malloc_initialize_hook) (void) = init_heap;
+compat_symbol_reference (libc, __malloc_initialize_hook,
+                         __malloc_initialize_hook, GLIBC_2_0);
 
 /* Simulate occasional unrelated heap activity in the non-dumped
    heap.  */
@@ -490,12 +490,5 @@ do_test (void)
 
   return errors;
 }
-#else
-static int
-do_test (void)
-{
-  return 77;
-}
-#endif
 
 #include <support/test-driver.c>