process: js fast path for cached bindings

[apapirovski]

Currently, both process.binding and internalBinding have to call into C++ regardless of whether the module has been cached or not. This creates significant overhead to all binding calls and unfortunately the rest of the codebase doesn't really optimize the amount of times that bindings are required (as an example: 12 files require the async_wrap binding).

Changing all the usage of this function throughout the codebase would introduce a lot of churn (and is kind of a hassle) so instead this PR introduces a JS fast path for both functions for cases where the binding has already been cached. While micro benchmarks are not super meaningful here (it's not like we call binding that often...), this does speed up the cached call by 400%.

Checklist

• make -j4 test (UNIX), or vcbuild test (Windows) passes
• commit message follows commit guidelines

Affected core subsystem(s)

process, src