fix(compiler): allow re-assigning inferred local object to another class - #95

Thanks for the analysis and the patch, @Tinywan. We don't accept this direction — to be direct: TypePHP does not allow re-assigning a variable to a different type, so this PR will be closed.

Rationale: TypePHP follows an AOT / static-compilation model. A variable's type is fixed from its first assignment (or explicit declaration). Assigning two unrelated concrete classes across mutually exclusive if/else branches means "one variable carrying different types", which is a type violation. Silently widening an inferred local into a generic dynamic object on those branches — as reassignInferredObjectVar() does here — invalidates every later static check that relies on that variable and bypasses the guarantees provided by stableObjects / declaredObjects. This kind of implicit widening/narrowing should not exist.

If you genuinely need a variable to hold different types across branches, declare it explicitly as any:

$a = 'strlen';
$ref = std::any();                    // dynamic object: any type/class can be assigned later
if (is_string($a)) {
    $ref = new ReflectionFunction($a);
} else {
    $ref = new ReflectionMethod($a, 'count');
}

Declaring the intent with std::any() keeps the compiler's checks sound. If reflection or another use case turns out to be more common, please open an issue with a real code path and we can discuss whether friendlier sugar is warranted.