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 6697e5c55b39e2d4718c7f89b5c995b98394e73b..0e820b7cc6ba95898c660be91eff476fa86d45e6 100644
--- a/runtime/vm/object.h
+++ b/runtime/vm/object.h
@@ -5349,6 +5349,8 @@ 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_;
@@ -5358,7 +5360,6 @@ 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_; }