`let f: T; f = (n) => ... f(n - 1)` at module scope threw "Cannot access
'f' before initialization": a function-typed (pointer-guarded) binding
kept the null-pointer TDZ test on its writes, but the declaration
already initialized it (to undefined) when it ran. Such bindings now
carry the existing initialization flag: the declaration sets it, writes
that can run earlier check it, and writes no longer test the empty
pointer. A write that really precedes the declaration still throws.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
