bring back runtime panic

Author: leongross

src/runtime/sync.go

@@ -6,12 +6,12 @@ package runtime
 func semacquire(sema *uint32) {
 	// TODO the "net" pkg calls this, so panic() isn't an option.  Right
 	// now, just ignore the call.
-	// panic("todo: semacquire")
+	panic("todo: semacquire")
 }
 
 //go:linkname semrelease internal/poll.runtime_Semrelease
 func semrelease(sema *uint32) {
 	// TODO the "net" pkg calls this, so panic() isn't an option.  Right
 	// now, just ignore the call.
-	// panic("todo: semrelease")
+	panic("todo: semrelease")
 }