OCaml and gcc on Windows

I installed OCaml for Windows from (https://fdopen.github.io/opam-repository-mingw/installation/). On the home page there is reference to the GCC compiler ("..the GCC compiler (mingw-w64) that will be used internally by the OCaml compiler in order to create native executables and libraries").

Would anyone know where on my hard drive this would have been installed and is the name "gcc"? I've tried searching my hard drive and cannnot find "gcc*.*".

Thanks!