[glibc/azanella/clang] elf: Suppress clang warning on tst-unique3

[Adhemerval Zanella <azanella@sourceware.org>]

https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=f017ab6a43873e2df26af262ad864c4bbdfcec8c

commit f017ab6a43873e2df26af262ad864c4bbdfcec8c
Author: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Date:   Fri Mar 25 11:17:39 2022 -0300

    elf: Suppress clang warning on tst-unique3
    
    clang warns that the instatiation of the variable is required,
    but no definition is available.  They are implemented on
    tst-unique3lib.so.
    
    Checked on x86_64-linux-gnu.

Diff:
---
 elf/tst-unique3.cc | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/elf/tst-unique3.cc b/elf/tst-unique3.cc
index efdd6d78c2..d07601fe6d 100644
--- a/elf/tst-unique3.cc
+++ b/elf/tst-unique3.cc
@@ -1,9 +1,14 @@
-#include "tst-unique3.h"
-
 #include <cstdio>
-#include "../dlfcn/dlfcn.h"
+#include <dlfcn.h>
+#include <libc-diag.h>
+#include "tst-unique3.h"
 
+/* clang warns that the instatiation of the variable is required, but no
+   definition is available.  They are implemented on tst-unique3lib.so.  */
+DIAG_PUSH_NEEDS_COMMENT_CLANG;
+DIAG_IGNORE_NEEDS_COMMENT_CLANG (13, "-Wundefined-var-template");
 int t = S<char>::i;
+DIAG_POP_NEEDS_COMMENT_CLANG;
 
 int
 main (void)