incorrect memoization of deeply nested lambda

```go
func h(x) {func f() {func g() {if x {1} else {2}}; g()}; f()}
log("h=",h(true))
Assert("boolean in nested lambda", h(true) == 1)
log("h=",h(false))
// BUG TODO/FIXME: g() inside f() is getting memoized/cached when it shouldn't be
Assert("boolean in nested lambda false", h(false) == 2)
```
h(false) after h(true) still returns 1 instead of 2
