bsd supports the same floating point classification functions as c99

Fixes inetd compile. From OpenWrt.

Signed-off-by: Leonid Lisovskiy <lly.dev@gmail.com>
Signed-off-by: Waldemar Brodkorb <wbx@uclibc-ng.org>

include/math.h

@@ -196,7 +196,7 @@ extern int signgam;
 
 
 /* ISO C99 defines some generic macros which work on any data type.  */
-#ifdef __USE_ISOC99
+#if defined(__USE_ISOC99) || defined(__USE_BSD)
 
 /* Get the architecture specific values describing the floating-point
    evaluation.  The following symbols will get defined:
@@ -316,6 +316,11 @@ enum
 
 #endif /* Use ISO C99.  */
 
+/* BSD compat */
+#define finite(x) __finite(x)
+#define finitef(x) __finitef(x)
+#define finitel(x) __finitel(x)
+
 #ifdef	__USE_MISC
 /* Support for various different standard error handling behaviors.  */
 typedef enum