redex: add typed generators to the benchmark

- change delim-cont to generate a store as well
- add version of rvm that works with #:satisfying
- add version of list-machine that works with #:satisfying
- new rewrites for the above
- infrastructure to wire all of this together
fix delim-cont tests
fix redex benchmark dependencies
Fix type for read-bitmap

Closes PR 14729
configure: add `--enable-natipkg` and 64-bit Linux native libraries

The `--enable-natipkg` configuration option adds "-natipkg" to the
platform library subpath. The suffix is intended to trigger the
installation of packages that supply native libraries for supported
platforms (where 64-bit Linux is the supported platform, for now, for
main-distribution packages), instead of relying on libraries installed
via the OS's package manager.

The intended client for "-natipkg" is the package-build service, where
installing packages via the OS package manager would require network
access and either trust or constrained installations. The build
machine is intentionally disconnected from the network and can only
access Racket packages, so repackaging native libraries as Racket
packages makes those libraries accessible.

A disadvantage of this approach to installing native libraries is that
it creates work for implementers of packages that access native
libraries. Those implementers will have to supply packages for 64-bit
Linux versions of native libraries to the degree needed to build and
(eventually) test the package. An advantage of the approach is that it
requires no changes to the package system; it will be cheap to replace
this approach if we find a better way to deal with native libraries
and/or OS packages in the package-build service.
distro-build: "detail" label rendering on download page
Use bytes consistently in regexmatch.

Inconsistency found by Tobias Pape, see GH issue #792.
redex: fix distribution cache in search
add missing file from previous push
Post-release version for the v6.1.1 release
Delete useless definition
redex: randomly choose between search heuristics
Rewrite TR class form to preserve abstractions

This uses a technique discovered by Ryan and Dan that
allows the typed class macro to function without invasively
local-expanding the entire class macro (using its private
context information).

Instead, it expands into many helper macros inside the
normal class body and communicates among them using
`syntax-local-value` and compile-time state within the
class body.

This rewrite didn't save that many lines, but it did
reduce the amount of magic that's used.
Get rid of some unused code.

Looks like some aborted attempt at abstraction, which is no longer used.
Get rid of `special-dots-printing?'.

Asumu said that he doesn't know of any other clients of this parameter
besides my class code.
Add `type-output-sexpr-tweaker'.

Sounds like a bad name, but I don't have anything better.  It's not some
"current-...-print" thing since it works on the sexpr that is intended
to be pretty-printed.  So I went with the above.
Random improvement.

The thing that caught my eye is the missing `#:cache-keys?' which should
really be there.  But not too important.
Fix printing of * in -> types
Add contract generation for Evtof types
add missing "x86_64-linux-natipkg" dependency

Merge to v6.1.1