fix: set size when alloca ArrayStorage

[github-actions[bot]]

Test262 conformance changes:

Test result	Dev count	PR count	Difference
Total	79,437	79,437	0
Passed	14,908	14,906	-2
Ignored	24,388	24,388	0
Failed	39,435	39,437	+2
Panics	706	706	0
Conformance	18.77	18.76	-0.00%

Base Failed But New Passed

``` 1. [non-strict] test262/test/built-ins/Object/keys/15.2.3.14-2-8.js ```

New Failed But Base Passed

``` 1. [non-strict] test262/test/built-ins/Object/create/15.2.3.5-4-39.js 2. [strict] test262/test/built-ins/Object/keys/15.2.3.14-2-8.js 3. [strict] test262/test/built-ins/Object/keys/15.2.3.14-3-1.js ```