With Bug 1662110, we would have the possibility of generating the stencils of inner functions eagerly. CompileLazyFunction should check whether a function was already computed by checking a cache which stores CompilationStencil of pre-compiled inner-functions.

This caching mechanism should also be instrumented to reports stats on the effectiveness of the caching strategies used to fill this cache such that we can compare various caching strategies. One metric would be the entropy of the cache registry with the cache query, to penalize strategies which are registering too many cache entry which are unused, and penalize strategies which are not registering enough cache entry.