Support generalized rewriting in let bindings

[mattam82]

Fixes / closes #????

• Added / updated test-suite.

• Added changelog.

• Opened overlay pull requests.
  • Adapt to Rocq PR # 20985 (backward compatible hint) stdlib#237

[mattam82]

@coqbot run full ci

[mattam82]

@coqbot bench

[SkySkimmer]

It seems like it timed out in PString?

[SkySkimmer]

@coqbot run full ci

[coqbot-app]

🔴 CI failures at commit 37c239a without any failure in the test-suite

✔️ Corresponding jobs for the base commit 00937db succeeded

❔ Ask me to try to extract minimal test cases that can be added to the test-suite

🏃 @coqbot ci minimize will minimize the following targets: ci-coq_performance_tests, ci-math_classes

• You can also pass me a specific list of targets to minimize as arguments.

[mattam82]

@coqbot run full ci

[SkySkimmer]

@coqbot run full ci

[coqbot-app]

🔴 CI failures at commit 37c239a without any failure in the test-suite

✔️ Corresponding jobs for the base commit c4fa328 succeeded

❔ Ask me to try to extract minimal test cases that can be added to the test-suite

🏃 @coqbot ci minimize will minimize the following targets: ci-coq_performance_tests, ci-math_classes

• You can also pass me a specific list of targets to minimize as arguments.