Auto merge of #13981 - Veykril:saveOnCheckStartup, r=Veykril

Don't run flycheck on startup unless checkOnSave is enabled

The main reason people disable it is because they don't want the expensive checks to occur automatically, so we shouldn't trigger them at the start up either if this is disabled.

crates/rust-analyzer/src/main_loop.rs

@@ -287,8 +287,10 @@ impl GlobalState {
                 || self.fetch_build_data_queue.op_requested());
 
             if became_quiescent {
-                // Project has loaded properly, kick off initial flycheck
-                self.flycheck.iter().for_each(FlycheckHandle::restart);
+                if self.config.check_on_save() {
+                    // Project has loaded properly, kick off initial flycheck
+                    self.flycheck.iter().for_each(FlycheckHandle::restart);
+                }
                 if self.config.prefill_caches() {
                     self.prime_caches_queue.request_op("became quiescent".to_string());
                 }