find package with multiple names pacman
Some packages like gcc-libs are apparently other packages, under a different name. turns out gcc-libs is just gcc: PKGBUILD
if I want to install that package, I know I can run pacman -S gcc-libs, but how can I find the original package, as in, the package which has a PKGBUILD named after it?
Those are called split packages (see PACKAGE SPLITTING section of PKGBUILD manual). I guess what you want is the pkgbase name and you can get that with pacinfo from pacutils e.g.
pacinfo lib32-gcc-libs
prints
Name: lib32-gcc-libs
Base: gcc
Repository: core
.................................
so the Base: key means pkgbase name, in this case gcc