contrib/tools/m4: Copy contrib/tools/bison solution to get rid of isnan{d,f,l}.c sources

commit_hash:31788279593d5a121af9f7d229957edabf1773e9

Author: georgthegreat

contrib/tools/m4/lib/config-win.h

@@ -1707,3 +1707,6 @@ char *strsignal (int signum);
 
 /* Define as a macro for copying va_list variables. */
 #define va_copy gl_va_copy
+
+#define HAVE_ISNANL_IN_LIBC 1
+#define HAVE_ISNAND_IN_LIBC 1

contrib/tools/m4/lib/isnand.c

@@ -84,9 +84,6 @@ SRCS(
     gl_oset.c
     gl_xlist.c
     gl_xoset.c
-    isnand.c
-    isnanl.c
-    isnanf.c
     localcharset.c
     lseek.c
     malloca.c