[Isolates] Merge r 6300:6500 from bleeding_edge to isolates.

src/scanner.cc

Index: src/scanner.cc
===================================================================
--- src/scanner.cc	(revision 6955)
+++ src/scanner.cc	(working copy)
@@ -48,14 +48,18 @@
 
 BufferedUC16CharacterStream::~BufferedUC16CharacterStream() { }
 
-void BufferedUC16CharacterStream::PushBack(uc16 character) {
+void BufferedUC16CharacterStream::PushBack(uc32 character) {
+  if (character == kEndOfInput) {
+    pos_--;
+    return;
+  }
   if (pushback_limit_ == NULL && buffer_cursor_ > buffer_) {
     // buffer_ is writable, buffer_cursor_ is const pointer.
-    buffer_[--buffer_cursor_ - buffer_] = character;
+    buffer_[--buffer_cursor_ - buffer_] = static_cast<uc16>(character);
     pos_--;
     return;
   }
-  SlowPushBack(character);
+  SlowPushBack(static_cast<uc16>(character));
 }