Fix spec violations related to regexp.lastIndex

src/regexp.js

Index: src/regexp.js
diff --git a/src/regexp.js b/src/regexp.js
index a3675f033248ba59ffb983967e7951476b3b1e67..da1883f3a427ec0edbdfd45af99e219071215b79 100644
--- a/src/regexp.js
+++ b/src/regexp.js
@@ -161,6 +161,7 @@ function RegExpExecNoTests(regexp, string, start) {
     lastMatchInfoOverride = null;
     return BuildResultFromMatchInfo(matchInfo, string);
   }
+  regexp.lastIndex = 0;
   return null;
 }
 
@@ -193,7 +194,7 @@ function RegExpExec(string) {
   var matchIndices = %_RegExpExec(this, string, i, lastMatchInfo);
 
   if (matchIndices === null) {
-    if (global) this.lastIndex = 0;
+    this.lastIndex = 0;
     return null;
   }
 
@@ -256,7 +257,10 @@ function RegExpTest(string) {
     %_Log('regexp', 'regexp-exec,%0r,%1S,%2i', [regexp, string, lastIndex]);
     // matchIndices is either null or the lastMatchInfo array.
     var matchIndices = %_RegExpExec(regexp, string, 0, lastMatchInfo);
-    if (matchIndices === null) return false;
+    if (matchIndices === null) {
+      this.lastIndex = 0;
+      return false;
+    }
     lastMatchInfoOverride = null;
     return true;
   }