Since the previous version of this code was first written, Racket's
requirements seem to have relaxed---but not completely!
If *all* related module paths are made relative, then the deps
test case breaks (but only the test is pre-compiled ?!!).
If requires from disappearing module(s) to residual module(s)
use absolute module paths, it seems to work.
The dance that syntax/parse performs to lazily load its implementation
rewrites uses of syntax/parse macros in such a way that their original
names were discarded, which shows up in error messages. By simply
invoking the underlying transformer directly in the proxy macro instead
of expanding to a rewritten use, users’ names can be preserved.
fixes#1909
