ECMAScript hoisting keeps the LAST function declaration with a given
name. The Rust scope_collector and script GDI extraction implemented
this with a single reverse scan that pushed first-seen entries, which
left the resulting list in REVERSE source order. The C++ side then
iterated `m_functions_to_initialize.in_reverse()` to undo that.
Switch the Rust side to a two-pass forward scan that records the last
position per name and emits entries in source order, and drop the
matching `.in_reverse()` calls in Script.cpp and AbstractOperations.cpp.
Same hoisting semantics; NewFunction emission and global property
iteration order now follow the source.
The HashMap that tracks last positions is keyed on `SharedUtf16String`,
so each insert is a refcount bump on the AST's existing Rc instead of
a deep `Vec<u16>` clone.
Add bytecode tests at script and nested-function scope that exercise
multiple declarations and a duplicate name to pin the new ordering.
