FunctionPointerCallResolver

This Pass is responsible for resolving function pointer calls, i.e., CallExpression nodes that contain a reference/pointer to a function and are being "called". This pass is intentionally split from the CallResolver because it depends on DFG edges. This split allows the CallResolver to be run before any DFG passes, which in turn allow us to also populate DFG passes for inferred functions.

This pass is currently only run for the CXXLanguageFrontend, however, in the future we might extend it to other languages that support some kind of function reference/pointer calling, such as Go.