fix "still mutable" ice while metrics are enabled

Author: yaahc

compiler/rustc_driver_impl/src/lib.rs

@@ -348,10 +348,6 @@ pub fn run_compiler(at_args: &[String], callbacks: &mut (dyn Callbacks + Send))
             // Make sure name resolution and macro expansion is run.
             let _ = tcx.resolver_for_lowering();
 
-            if let Some(metrics_dir) = &sess.opts.unstable_opts.metrics_dir {
-                dump_feature_usage_metrics(tcx, metrics_dir);
-            }
-
             if callbacks.after_expansion(compiler, tcx) == Compilation::Stop {
                 return early_exit();
             }
@@ -370,6 +366,10 @@ pub fn run_compiler(at_args: &[String], callbacks: &mut (dyn Callbacks + Send))
 
             tcx.ensure_ok().analysis(());
 
+            if let Some(metrics_dir) = &sess.opts.unstable_opts.metrics_dir {
+                dump_feature_usage_metrics(tcx, metrics_dir);
+            }
+
             if callbacks.after_analysis(compiler, tcx) == Compilation::Stop {
                 return early_exit();
             }