Make compile-time errors catchable

runtime/vm/object.h

Index: runtime/vm/object.h
diff --git a/runtime/vm/object.h b/runtime/vm/object.h
index b502dfcd3558f8c4d33e5a19a39bdbc8c12f8267..506494670118823f0ae0963d23238b0602d3f6a4 100644
--- a/runtime/vm/object.h
+++ b/runtime/vm/object.h
@@ -5219,6 +5219,8 @@ class LanguageError : public Error {
 
   virtual const char* ToErrorCString() const;
 
+  TokenPosition token_pos() const { return raw_ptr()->token_pos_; }
+
  private:
   RawError* previous_error() const {
     return raw_ptr()->previous_error_;
@@ -5228,7 +5230,6 @@ class LanguageError : public Error {
   RawScript* script() const { return raw_ptr()->script_; }
   void set_script(const Script& value) const;
 
-  TokenPosition token_pos() const { return raw_ptr()->token_pos_; }
   void set_token_pos(TokenPosition value) const;
 
   bool report_after_token() const { return raw_ptr()->report_after_token_; }