Force local compilation with -fsantize-blacklist (UBSAN)
Force local compilation with -fsantize-blacklist (UBSAN)

Icecream currently can't distribute the blacklist file [1] which causes the
compiles to fail when run on a remote node. This commit both prevents remote
execution of compiles with that flag and limits concurrency to NUM_CORES so
you don't OOM yourself if you forget to lower your -j setting.

[1] https://github.com/icecc/icecream/issues/266

RedBeard0531/mongo_module_ninja,RedBeard0531/mongo_module_ninja,RedBeard0531/mongo_module_ninja