The parser only set `might_need_arguments_object` when an `arguments`
or `eval` Identifier went through `consume()`, but shorthand object
properties create the reference via `make_identifier()` directly. As
a result `function f() { return { arguments } }` allocated an
`arguments` local, never initialized it, and crashed at runtime when
the property was read.
Fall back to scope-driven detection: if scope analysis allocated a
non-lexical `arguments` local for the function, treat it as a real
arguments-object reference and emit `CreateArguments`. Skip the
fallback when a function declaration named `arguments` claims the
local, since that local belongs to the function, not the arguments
object.
Add a runtime test covering shorthand inside a free function and a
method, plus a regression test for `({ eval } = ...)` to confirm
destructuring assignment doesn't accidentally trigger arguments
materialization.
e65e85cb8c