Add goroutines and function pointers

src/runtime/runtime.go

@@ -6,6 +6,13 @@ const Compiler = "tgo"
 // The bitness of the CPU (e.g. 8, 32, 64). Set by the compiler as a constant.
 var TargetBits uint8
 
+func Sleep(d Duration) {
+	// This function is treated specially by the compiler: when goroutines are
+	// used, it is transformed into a llvm.coro.suspend() call.
+	// When goroutines are not used this function behaves as normal.
+	sleep(d)
+}
+
 func _panic(message interface{}) {
 	printstring("panic: ")
 	printitf(message)