gccrs: Fix use rebind name resolution.
Name resolution for rebind were missing.
gcc/rust/ChangeLog:
* resolve/rust-toplevel-name-resolver-2.0.cc (TopLevel::handle_use_glob):
Change function prototype to use a reference instead.
(TopLevel::handle_use_dec): Likewise.
(TopLevel::handle_rebind): Add name resolution on rebind use
declarations.
(flatten_rebind): Change prototype to accept a pair of path/alias.
(flatten_list): Adapt call to flatten_rebind.
(flatten): Adapt call to flatten_rebind.
(flatten_glob): Remove unused part.
(TopLevel::visit): Add rebind resolution.
* resolve/rust-toplevel-name-resolver-2.0.h: Adapt function prototypes.
Signed-off-by: Pierre-Emmanuel Patry <pierre-emmanuel.patry@embecosm.com>