extend stdlib to allow import of more packages (#1099)

* stdlib: extend stdlib to allow import of more packages

src/runtime/error.go

@@ -0,0 +1,8 @@
+package runtime
+
+// The Error interface identifies a run time error.
+type Error interface {
+	error
+
+	RuntimeError()
+}

src/runtime/stack.go

@@ -14,3 +14,7 @@ func (f *Func) Name() string {
 func Caller(skip int) (pc uintptr, file string, line int, ok bool) {
 	return 0, "", 0, false
 }
+
+func Stack(buf []byte, all bool) int {
+	return 0
+}