String equality improvements.

src/objects-inl.h

Index: src/objects-inl.h
diff --git a/src/objects-inl.h b/src/objects-inl.h
index c7d93e3fb51811a48d867db90827f39d8b2b0fca..da814a0e454da2d4676e903230720ea927961ce0 100644
--- a/src/objects-inl.h
+++ b/src/objects-inl.h
@@ -125,6 +125,12 @@ bool Object::IsSeqAsciiString() {
 }
 
 
+bool String::IsSeqAsciiString() {
+  return (this->representation_tag() == kSeqStringTag)
+    && is_ascii_representation();
+}
+
+
 bool Object::IsSeqTwoByteString() {
   return IsSeqString()
       && !String::cast(this)->IsAsciiRepresentation();
@@ -1408,6 +1414,11 @@ Address SeqAsciiString::GetCharsAddress() {
 }
 
 
+const char* SeqAsciiString::GetChars() {
+  return reinterpret_cast<const char*>(GetCharsAddress());
+}
+
+
 Address SeqTwoByteString::GetCharsAddress() {
   return FIELD_ADDR(this, kHeaderSize);
 }