Cache compile-time constants on the script object, sometimes.

runtime/vm/object.h

Index: runtime/vm/object.h
diff --git a/runtime/vm/object.h b/runtime/vm/object.h
index 4dcade6c39e0b0a554092e1c31455df1c2041889..3cee2718e21e3e17abed052ad0c575603d263039 100644
--- a/runtime/vm/object.h
+++ b/runtime/vm/object.h
@@ -3477,6 +3477,11 @@ class Script : public Object {
   // The load time in milliseconds since epoch.
   int64_t load_timestamp() const { return raw_ptr()->load_timestamp_; }
 
+  RawArray* compile_time_constants() const {
+    return raw_ptr()->compile_time_constants_;
+  }
+  void set_compile_time_constants(const Array& value) const;
+
   RawTokenStream* tokens() const { return raw_ptr()->tokens_; }
 
   void Tokenize(const String& private_key,