Experimental Profiler: tweak type info threshold.

src/string.js

Index: src/string.js
diff --git a/src/string.js b/src/string.js
index 02f5c98cd3aee7eefe5965953c6420feb1237442..3caaff43df91563faac196fd2d1a83bdb6fd200d 100644
--- a/src/string.js
+++ b/src/string.js
@@ -554,14 +554,14 @@ function StringSlice(start, end) {
     }
   } else {
     if (start_i > s_len) {
-      start_i = s_len;
+      return '';
     }
   }
 
   if (end_i < 0) {
     end_i += s_len;
     if (end_i < 0) {
-      end_i = 0;
+      return '';
     }
   } else {
     if (end_i > s_len) {
@@ -569,12 +569,11 @@ function StringSlice(start, end) {
     }
   }
 
-  var num_c = end_i - start_i;
-  if (num_c < 0) {
-    num_c = 0;
+  if (end_i <= start_i) {
+    return '';
   }
 
-  return SubString(s, start_i, start_i + num_c);
+  return SubString(s, start_i, end_i);
 }