dillon1000/react

[compiler][bugfix] Bail out when a memo block declares hoisted fns (#32765)

Note that bailing out adds false positives for hoisted functions whose
only references are within other functions. For example, this rewrite
would be safe.
```js
// source program
  function foo() {
    return bar();
  }
  function bar() {
    return 42;
  }

// compiler output
let bar;
if (/* deps changed */) {
  function foo() {
    return bar();
  }
  bar = function bar() {
    return 42;
  }
}
```
These false positives are difficult to detect because any maybe-call of
foo before the definition of bar would be invalid.

Instead of bailing out, we should rewrite hoisted function declarations
to the following form.
```js
let bar$0;
if (/* deps changed */) {
  // All references within the declaring memo block
  // or before the function declaration should use
  // the original identifier `bar`
  function foo() {
    return bar();
  }
  function bar() {
    return 42;
  }
  bar$0 = bar;
}
// All references after the declaring memo block
// or after the function declaration should use
// the rewritten declaration `bar$0`
```