snan tests: Fix "unused variable" warnings on i386

[Bruno Haible]

In the 'snan' tests, I see warnings about unused variables 'nanf', 'nand'.
This patch silences them.


2023-10-14  Bruno Haible  <bruno@clisp.org>

        snan tests: Fix "unused variable" warnings on i386.
        * tests/test-snan-1.c (main): Mark nanf, nand, nanl as possibly unused.
        * tests/test-snan-2.c (main): Likewise.

diff --git a/tests/test-snan-1.c b/tests/test-snan-1.c
index 911d20bd70..7b71b9a57b 100644
--- a/tests/test-snan-1.c
+++ b/tests/test-snan-1.c
@@ -56,9 +56,9 @@ main ()
      The use of 'volatile' prevents the compiler from doing constant-folding
      optimizations on these values.  An alternative, for GCC only, would be
      the command-line option '-fsignaling-nans'.  */
-  float volatile nanf = SNaNf ();
-  double volatile nand = SNaNd ();
-  long double volatile nanl = SNaNl ();
+  _GL_UNUSED float volatile nanf = SNaNf ();
+  _GL_UNUSED double volatile nand = SNaNd ();
+  _GL_UNUSED long double volatile nanl = SNaNl ();
 
   /* Check that the values are really signalling.  */
   /* These tests do not work on 32-bit x86 processors, as well as
diff --git a/tests/test-snan-2.c b/tests/test-snan-2.c
index 4ddd3ac9b1..5e5940609c 100644
--- a/tests/test-snan-2.c
+++ b/tests/test-snan-2.c
@@ -44,9 +44,9 @@ main (int argc, char *argv[])
      The use of 'volatile' prevents the compiler from doing constant-folding
      optimizations on these values.  An alternative, for GCC only, would be
      the command-line option '-fsignaling-nans'.  */
-  float volatile nanf = SNaNf ();
-  double volatile nand = SNaNd ();
-  long double volatile nanl = SNaNl ();
+  _GL_UNUSED float volatile nanf = SNaNf ();
+  _GL_UNUSED double volatile nand = SNaNd ();
+  _GL_UNUSED long double volatile nanl = SNaNl ();
 
   /* Check that the values are really signalling.  */