libtest: also measure time in Miri

Author: RalfJung

library/test/src/console.rs

@@ -315,10 +315,8 @@ pub fn run_tests_console(opts: &TestOpts, tests: Vec<TestDescAndFn>) -> io::Resu
 
     // Prevent the usage of `Instant` in some cases:
     // - It's currently not supported for wasm targets.
-    // - We disable it for miri because it's not available when isolation is enabled.
-    let is_instant_unsupported = (cfg!(target_family = "wasm") && !cfg!(target_os = "wasi"))
-        || cfg!(target_os = "zkvm")
-        || cfg!(miri);
+    let is_instant_unsupported =
+        (cfg!(target_family = "wasm") && !cfg!(target_os = "wasi")) || cfg!(target_os = "zkvm");
 
     let start_time = (!is_instant_unsupported).then(Instant::now);
     run_tests(opts, tests, |x| on_test_event(&x, &mut st, &mut *out))?;

src/bootstrap/src/utils/render_tests.rs

@@ -377,7 +377,7 @@ struct SuiteOutcome {
     measured: usize,
     filtered_out: usize,
     /// The time it took to execute this test suite, or `None` if time measurement was not possible
-    /// (e.g. due to running inside Miri).
+    /// (e.g. due to running on wasm).
     exec_time: Option<f64>,
 }