src: replace IsConstructCall functions with lambda

I noticed that there are three static functions that only check if
args is a construct call. This commit suggests replacing them and
them with a lambda.

PR-URL: https://github.com/nodejs/node/pull/12384


Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: James M Snell <jasnell@gmail.com>