Add Duration.*

This allows multiplying a Duration with an Int, such as
`Duration.from_secs(1) * 5`.

Changelog: added

std/src/std/time.inko

@@ -4,7 +4,7 @@ import std.cmp (Compare, Equal, Ordering)
 import std.float (ToFloat)
 import std.fmt (Format, Formatter)
 import std.int (ToInt)
-import std.ops (Add, Subtract)
+import std.ops (Add, Multiply, Subtract)
 
 fn extern inko_time_monotonic(state: Pointer[UInt8]) -> Int64
 
@@ -191,6 +191,12 @@ impl Subtract[Duration, Duration] for Duration {
   }
 }
 
+impl Multiply[Int, Duration] for Duration {
+  fn pub *(other: ref Int) -> Duration {
+    Duration(@nanos * other)
+  }
+}
+
 impl Compare[Duration] for Duration {
   fn pub cmp(other: ref Duration) -> Ordering {
     @nanos.cmp(other.nanos)

std/test/std/test_time.inko

@@ -74,6 +74,14 @@ fn pub tests(t: mut Tests) {
     Duration.from_nanos(-9_223_372_036_854_775_808) - Duration.from_nanos(1)
   })
 
+  t.test('Duration.*', fn (t) {
+    t.equal(Duration.from_secs(1) * 5, Duration.from_secs(5))
+  })
+
+  t.panic('Duration.* with an argument that overflows', fn {
+    Duration.from_secs(1) * -9_223_372_036_854_775_808
+  })
+
   t.test('Duration.cmp', fn (t) {
     let a = Duration.from_secs(1)
     let b = Duration.from_secs(2)