This PR adds the ability to enable the GIL if it was disabled at
interpreter startup, and modifies the multi-phase module initialization
path to enable the GIL when loading a module, unless that module's spec
includes a slot indicating it can run safely without the GIL.
PEP 703 called the constant for the slot `Py_mod_gil_not_used`; I went
with `Py_MOD_GIL_NOT_USED` for consistency with gh-104148.
A warning will be issued up to once per interpreter for the first
GIL-using module that is loaded. If `-v` is given, a shorter message
will be printed to stderr every time a GIL-using module is loaded
(including the first one that issues a warning).
This matches the GIL releasing behavior of our existing `_hashopenssl`
module, extending it to the HACL* built-ins.
Includes adding comments to better describe the ENTER/LEAVE macros
purpose and explain the lock strategy in both existing and new code.
Replaces our built-in SHA3 implementation with a verified one from the HACL* project.
This implementation is used when OpenSSL does not provide SHA3 or is not present.
3.11 shiped with a very slow tiny sha3 implementation to get off of the <=3.10 reference implementation that wound up having serious bugs. This brings us back to a reasonably performing built-in implementation consistent with what we've just replaced our other guaranteed available standard hash algorithms with: code from the HACL* project.
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Co-authored-by: Gregory P. Smith <greg@krypto.org>
