Run Nick G's spellchecker github.com/client9/misspell, carefuly fix what it found (#4235)

src/runtime/interrupt/interrupt.go

@@ -26,7 +26,7 @@ func New(id int, handler func(Interrupt)) Interrupt
 // and use that in an Interrupt object. That way the compiler will be able to
 // optimize away all interrupt handles that are never used in a program.
 // This system only works when interrupts need to be enabled before use and this
-// is done only through calling Enable() on this object. If interrups cannot
+// is done only through calling Enable() on this object. If interrupts cannot
 // individually be enabled/disabled, the compiler should create a pseudo-call
 // (like runtime/interrupt.use()) that keeps the interrupt alive.
 type handle struct {