Assigning a prop to an imported object, breaks initial run of reactive statements

[jakobrosenberg]

Describe the bug
Imported objects don't work in reactive statements if there's an assignment to the object.

To Reproduce
https://svelte.dev/repl/5f4423eaf63644dfa71578997b0b0d4c?version=3.19.2

Expected behavior
The reactive statement should be executed on load

Severity
Severe since the bug doesn't show any warnings and thus can break apps without a way to track it down.

Additional context
Reassigning the imported object fixes the bug:

  import {obj as importedObj} from './obj.js'
  const obj = importedObj

[pushkine]

here is another repl of the bug
https://svelte.dev/repl/41ada46cf7e04922852fe34a0b32582d?version=3.20.1

here is a test + bad fix that puts every import into ctx
https://github.com/pushkine/svelte/tree/object-ext

the fix requires to check that

• the object is mutated locally
• some local state depends on it

I'm not familiar enough with the structure to do that myself

[Conduitry]

This has been fixed in 3.22.0 - https://svelte.dev/repl/5f4423eaf63644dfa71578997b0b0d4c?version=3.22.0