[fpcmp] Use stdbool.h instead of typedef

The typedef produces a compilation error with GCC 15.

Author: nikic

tools/fpcmp.c

@@ -12,6 +12,7 @@
 
 #include <ctype.h>
 #include <math.h>
+#include <stdbool.h>
 #include <stddef.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -21,10 +22,6 @@ const char *g_program;
 
 /* *** */
 
-typedef int bool;
-#define true ((bool) 1)
-#define false ((bool) 0)
-
 static bool isSignedChar(char C) {
   return (C == '+' || C == '-');
 }