Follows the basic shallow-clone pattern of type::Manager::Wrap(),
which this new method uses.
Use ProgramBuilder::Wrap() in the writers, where we were previously
using type::Manager::Wrap(). This simplifies some of the logic
(especially around AppendVector()).
This is now required as semantic information is generated inside the
writers for newly constructed AST nodes, and we need to register
this semantic info so it can be fetched later.
Change-Id: Ia362204a1f13054e50545baeb7d269f210a36826
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/39004
Commit-Queue: Ben Clayton <bclayton@google.com>
Reviewed-by: dan sinclair <dsinclair@chromium.org>