Small updates

Allow 'make speedtest' in tests directory
Fix compiler warning tccpp.c

examples/ex3.c

@@ -1,6 +1,6 @@
 #include <tcclib.h>
 
-int fib(n)
+int fib(int n)
 {
     if (n <= 2)
         return 1;
@@ -18,6 +18,6 @@ int main(int argc, char **argv)
     }
 
     n = atoi(argv[1]);
-    printf("fib(%d) = %d\n", n, fib(n, 2));
+    printf("fib(%d) = %d\n", n, fib(n));
     return 0;
 }

tccpp.c

@@ -2575,12 +2575,13 @@ static void parse_number(const char *p)
             if (t >= b)
                 tcc_error("invalid digit");
             n = n * b + t;
-            if (!ov)
+            if (!ov) {
                 /* detect overflow */
                 if (n1 >= 0x1000000000000000ULL && n / b != n1)
                     ov = 1;
                 else
                     n1 = n;
+	    }
         }
 #ifdef TCC_CUT_ON_INTEGER_LITERAL_OVERFLOW
         /* On integer literal overflow use the most significant digits before