A `module-suffixes` entry in a collection's "info.rkt" adds a
file suffix that is meant to be recognized globally (i.e., in
all collections) by all Racket tools.
The new fields are reported by `compiler/module-suffix` library, which
is (so far) used by `raco setup`.
Note that if package A includes files with a suffix that is registered
by package B, then A should have a dependency on B, but `raco setup`
cannot currently detect that such a dependency is needed. That
dependency is likely to happen, anyway, since package A is likely
using libraries form package B.
Comments in the implementation suggest that a timestamp
specialization was intended for directories, which makes
sense given that directory-modification dates are
not preserved when unpacking an archive. The change
also affected all bytecode timestamps, however, which
can create inconsistencies across package creations.
The `from` string argument is converted to a regexp and cached. When `from` is
a mutable string this can cause wrong results in the following calls
to string-replace. So the string is first converted to an immutable string to
be used as the key for the cache.
When `place` expands, the body of the `place` form is placed into a
`(module* place-body-<n> #f ....)` submodule.
The `place` form previously placed its body in a lifted function,
where the function's exported name was based on
`(current-inexact-milliseconds)`. The generated submodules have
deterministic names, so that compilation is deterministic, and
submodule names don't collide (unlike exported function names) when
multiple `place`-using module are imported into some other module.
Also, using a submodule avoids the problem that the clock doesn't
change fast enough on Windows.
Those aliases were moved out of `#%kernel` as part of the
determinstic-bytecode changes, but putting them in
`racket/private/pre-base` meant that they weren't included in
`mzscheme` or Pretty Big. The new location is with `let/cc`, which
makes more sense, and makes them picked up by `mzscheme` and Pretty
Big.
