Tentative implementation of string slices (hidden under the flag --string-slices).

src/handles.cc

Index: src/handles.cc
diff --git a/src/handles.cc b/src/handles.cc
index d73aaf0fca671fed228d4996c5e70872713eee8e..8a14eac47a2df279547c8f7dd39b1d02ed7b2c3d 100644
--- a/src/handles.cc
+++ b/src/handles.cc
@@ -250,6 +250,21 @@ Handle<String> FlattenGetString(Handle<String> string) {
 }
 
 
+void TruncateString(Handle<String> string) {
+  CALL_HEAP_FUNCTION_VOID(string->GetIsolate(), string->TryTruncate());
+}
+
+
+Handle<String> TruncateGetString(Handle<String> string) {
+  CALL_HEAP_FUNCTION(string->GetIsolate(), string->TryTruncate(), String);
+}
+
+
+void FlattenOrTruncateString(Handle<String> string) {
+  CALL_HEAP_FUNCTION_VOID(string->GetIsolate(), string->TryFlattenOrTruncate());
+}
+
+
 Handle<Object> SetPrototype(Handle<JSFunction> function,
                             Handle<Object> prototype) {
   ASSERT(function->should_have_prototype());