Make RegExp constructor non-const.

sdk/lib/html/templates/html/impl/impl_Document.darttemplate

Index: sdk/lib/html/templates/html/impl/impl_Document.darttemplate
diff --git a/sdk/lib/html/templates/html/impl/impl_Document.darttemplate b/sdk/lib/html/templates/html/impl/impl_Document.darttemplate
index 5987b46720991a2a81be9f5073bc0f1554d51753..e97e913ab5906390982823659012e3f3ea3d1842 100644
--- a/sdk/lib/html/templates/html/impl/impl_Document.darttemplate
+++ b/sdk/lib/html/templates/html/impl/impl_Document.darttemplate
@@ -16,14 +16,14 @@ $!MEMBERS
   Element query(String selectors) {
     // It is fine for our RegExp to detect element id query selectors to have
     // false negatives but not false positives.
-    if (const RegExp("^#[_a-zA-Z]\\w*\$").hasMatch(selectors)) {
+    if (new RegExp("^#[_a-zA-Z]\\w*\$").hasMatch(selectors)) {
       return $dom_getElementById(selectors.substring(1));
     }
     return $dom_querySelector(selectors);
   }
 
   List<Element> queryAll(String selectors) {
-    if (const RegExp("""^\\[name=["'][^'"]+['"]\\]\$""").hasMatch(selectors)) {
+    if (new RegExp("""^\\[name=["'][^'"]+['"]\\]\$""").hasMatch(selectors)) {
       final mutableMatches = $dom_getElementsByName(
           selectors.substring(7,selectors.length - 2));
       int len = mutableMatches.length;
@@ -32,7 +32,7 @@ $!MEMBERS
         copyOfMatches[i] = mutableMatches[i];
       }
       return new _FrozenElementList._wrap(copyOfMatches);
-    } else if (const RegExp("^[*a-zA-Z0-9]+\$").hasMatch(selectors)) {
+    } else if (new RegExp("^[*a-zA-Z0-9]+\$").hasMatch(selectors)) {
       final mutableMatches = $dom_getElementsByTagName(selectors);
       int len = mutableMatches.length;
       final copyOfMatches = new List<Element>(len);