[Compiler] Align memoization of function expression properties with method shorthand #36151

[Bobadu]

The compiler memoizes { foo() {} } and { foo: () => {} } differently — method shorthand gets the whole object in one scope, function expressions get split into separate cache slots. Same semantics, different output.

The issue is in AlignObjectMethodScopes — it only looks at ObjectMethod instructions when deciding what to merge. This extends it to also pick up FunctionExpression values used as object properties.

Fixes #36151

[josephsavona]

Thanks for the contribution! However, this is backwards. The reason we merge object methods with their object is that we're currently trying to preserve the fact that they are object methods at all (i mean syntactically in our codegen output). But since we don't support this, we actually don't have to keep object methods as object methods. So the more optimal thing to do here is actually rewrite object methods into function expressions, and remove AlignObjectMethodScopes altogether.