malloc: Fix mallinfo deprecation declaration

It fixes the build issue below introduced by e3960d1c57e57 (Add
mallinfo2  function that support sizes >= 4GB).  It moves the
__MALLOC_DEPRECATED to the usual place for function attributes:

  In file included from ../include/malloc.h:3,
                   from ../sysdeps/x86_64/multiarch/../../../test-skeleton.c:31,
                   from ../sysdeps/x86_64/multiarch/test-multiarch.c:96:
  ../malloc/malloc.h:118:1: error: empty declaration [-Werror]
    118 | __MALLOC_DEPRECATED;

It also adds the required deprecated warning suppression on the tests.

Checked on x86_64-linux-gnu.

1 files changed, 7 insertions, 0 deletions

diff --git a/malloc/tst-mxfast.c b/malloc/tst-mxfast.c
index 57b4a0a8dc..8afee0f9d5 100644
--- a/malloc/tst-mxfast.c
+++ b/malloc/tst-mxfast.c
@@ -21,6 +21,7 @@
    the fast bins.  */
 
 #include <malloc.h>
+#include <libc-diag.h>
 #include <support/check.h>
 
 int
@@ -36,8 +37,14 @@ do_test (void)
   p2 = malloc (512);
   free (p1);
 
+  /* The test below covers the deprecated mallinfo function.  */
+  DIAG_PUSH_NEEDS_COMMENT;
+  DIAG_IGNORE_NEEDS_COMMENT (4.9, "-Wdeprecated-declarations");
+
   m = mallinfo ();
 
+  DIAG_POP_NEEDS_COMMENT;
+
   /* This will fail if there are any blocks in the fastbins.  */
   TEST_COMPARE (m.smblks, 0);