make harden-exports aware that Pattern makers are already hardened

[turadg]

What is the Problem Being Solved?

For all M.something(...), we should assume that it produces a properly hardened value and omit the noise. (context)

Description of the Design

Update the lint rule to detect if the exported value is the result of an M.something call, and if so consider that already hardened.

Security Considerations

Scaling Considerations

Test Plan

Compatibility Considerations

Upgrade Considerations

[erights]

For a lint rule, I suggest something even weaker. Rather than noticing M.something(...) expressions specifically, notice (at least top level) declarations initialized to literal expressions, such as function literals, object literals, array literals, etc. For these, ensure that the initialized variable is hardened before any code could observe the resulting value in a non-hardened state.

For everything other than literal expressions, the lint rule should pass on them, and we should take care elsewhere to ensure that these non-literal expressions produce values that are already hardened.