Rollup merge of #156133 - RalfJung:time-panic-track-caller, r=Mark-Simulacrum

mark some panicking methods around Duration as track_caller

Currently when they panic it looks like this
```
  0.005045   ---- instant_checked_duration_since_nopanic stdout ----
  0.000039
  0.000009   thread 'instant_checked_duration_since_nopanic' (2) panicked at /home/runner/work/miri-test-libstd/miri-test-libstd/rust-src-patched/library/std/src/time.rs:445:33:
  0.000007   overflow when subtracting duration from instant
  0.000006   note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
  0.000007   note: in Miri, you may have to set `MIRIFLAGS=-Zmiri-env-forward=RUST_BACKTRACE` for the environment variable to have an effect
```
That's pretty useless.

Also fix the panic message while we are at it.

Author: JonathanBrouwer

library/std/src/time.rs

@@ -425,6 +425,7 @@ impl Add<Duration> for Instant {
     ///
     /// This function may panic if the resulting point in time cannot be represented by the
     /// underlying data structure. See [`Instant::checked_add`] for a version without panic.
+    #[track_caller]
     fn add(self, other: Duration) -> Instant {
         self.checked_add(other).expect("overflow when adding duration to instant")
     }
@@ -441,6 +442,7 @@ impl AddAssign<Duration> for Instant {
 impl Sub<Duration> for Instant {
     type Output = Instant;
 
+    #[track_caller]
     fn sub(self, other: Duration) -> Instant {
         self.checked_sub(other).expect("overflow when subtracting duration from instant")
     }
@@ -742,8 +744,9 @@ impl Add<Duration> for SystemTime {
     ///
     /// This function may panic if the resulting point in time cannot be represented by the
     /// underlying data structure. See [`SystemTime::checked_add`] for a version without panic.
+    #[track_caller]
     fn add(self, dur: Duration) -> SystemTime {
-        self.checked_add(dur).expect("overflow when adding duration to instant")
+        self.checked_add(dur).expect("overflow when adding duration to `SystemTime`")
     }
 }
 
@@ -758,8 +761,9 @@ impl AddAssign<Duration> for SystemTime {
 impl Sub<Duration> for SystemTime {
     type Output = SystemTime;
 
+    #[track_caller]
     fn sub(self, dur: Duration) -> SystemTime {
-        self.checked_sub(dur).expect("overflow when subtracting duration from instant")
+        self.checked_sub(dur).expect("overflow when subtracting duration from `SystemTime`")
     }
 }