fix test on those platforms where infinity is not "INF", but "Infinity"

tests/lang/bug24640.phpt

@@ -35,7 +35,7 @@ test(1.7e-1000);
 ?>
 ===DONE===
 <?php exit(0); ?>
---EXPECT--
+--EXPECTF--
 1.7E+300
 float(1.7E+300)
 1.7E+300
@@ -76,50 +76,50 @@ float(1.7E-81)
 1.7E-81
 1.7E-81
 ------
-INF
-float(INF)
-INF
-INF
+I%s
+float(I%s)
+I%s
+I%s
 ------
 1.69998107421E-319
 float(1.69998107421E-319)
 1.69998107421E-319
 1.69998107421E-319
 ------
-INF
-float(INF)
-INF
-INF
+I%s
+float(I%s)
+I%s
+I%s
 ------
 1.70007988734E-320
 float(1.70007988734E-320)
 1.70007988734E-320
 1.70007988734E-320
 ------
-INF
-float(INF)
-INF
-INF
+I%s
+float(I%s)
+I%s
+I%s
 ------
 1.69958582169E-321
 float(1.69958582169E-321)
 1.69958582169E-321
 1.69958582169E-321
 ------
-INF
-float(INF)
-INF
-INF
+I%s
+float(I%s)
+I%s
+I%s
 ------
 0
 float(0)
 0
 0
 ------
-INF
-float(INF)
-INF
-INF
+I%s
+float(I%s)
+I%s
+I%s
 ------
 0
 float(0)