[Experimental] Non-reentrancy special form

[jmcardon]

This PR is a proof of concept of an experimental feature for pact 5, which is module level non-reentrancy.

Syntax

For some syntactic term k,

(non-reentrant k)

Semantics

For any term k (in this example, (m::foo 1)) written within a module foo's definition (defcap, defun, defpact), e.g:

  (defun definitely-not-reentrant (m:module{foo-callable})
    (with-capability (SENSITIVE)
      ; NAME IS TENTATIVE
      (non-reentrant (m::foo 1))
      (called-internal)
      )
  )

(non-reentrant k) guarantees that k does not call back into foo during evaluation of k.

PR checklist:

• Test coverage for the proposed changes
• PR description contains example output from repl interaction or a snippet from unit test output
• (If Relevant) Documentation has been (manually) updated at https://docs.kadena.io/pact

Additionally, please justify why you should or should not do the following:

• Benchmark regressions
• Confirm replay/back compat (Ignore until core release)
• (For Kadena engineers) Run integration-tests against a Chainweb built with this version of Pact (Ignore until core release)

[CryptoPascal31]

❤️ 👍 👍