fpu/softfloat: Make is_nan et al available to softfloat-specialize.h

We will need these helpers within softfloat-specialize.h, so move
the definitions above the include.  After specialization, they will
not always be used so mark them to avoid the Werror.
Tested-by: NAlex Bennée <alex.bennee@linaro.org>
Reviewed-by: NAlex Bennée <alex.bennee@linaro.org>
Reviewed-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NRichard Henderson <richard.henderson@linaro.org>

fpu/softfloat.c

@@ -181,6 +181,22 @@ typedef enum __attribute__ ((__packed__)) {
     float_class_snan,
 } FloatClass;
 
+/* Simple helpers for checking if, or what kind of, NaN we have */
+static inline __attribute__((unused)) bool is_nan(FloatClass c)
+{
+    return unlikely(c >= float_class_qnan);
+}
+
+static inline __attribute__((unused)) bool is_snan(FloatClass c)
+{
+    return c == float_class_snan;
+}
+
+static inline __attribute__((unused)) bool is_qnan(FloatClass c)
+{
+    return c == float_class_qnan;
+}
+
 /*
  * Structure holding all of the decomposed parts of a float. The
  * exponent is unbiased and the fraction is normalized. All
@@ -536,20 +552,6 @@ static float64 float64_round_pack_canonical(FloatParts p, float_status *s)
     return float64_pack_raw(round_canonical(p, s, &float64_params));
 }
 
-/* Simple helpers for checking if what NaN we have */
-static bool is_nan(FloatClass c)
-{
-    return unlikely(c >= float_class_qnan);
-}
-static bool is_snan(FloatClass c)
-{
-    return c == float_class_snan;
-}
-static bool is_qnan(FloatClass c)
-{
-    return c == float_class_qnan;
-}
-
 static FloatParts return_nan(FloatParts a, float_status *s)
 {
     switch (a.cls) {