Expand list of always loaded Windows shared libs

When the `GCC` driver envokes the pipeline a `SPEC` is used to determine
how to configure the compiler and which libraries to pass along.

For Windows/mingw, this specfile is
https://github.com/gcc-mirror/gcc/blob/master/gcc/config/i386/mingw32.h

This expands the list of base DLLs with the ones that GCC always links,
and adds extra sibling dlls of `stdc++` in case it is linked in.

Following D3028 this patch only needs to load the always load only the
top level individual shared libs.

Test Plan: ./validate

Reviewers: RyanGlScott, austin, bgamari, erikd, simonmar

Reviewed By: bgamari

Subscribers: RyanGlScott, thomie, #ghc_windows_task_force

Differential Revision: https://phabricator.haskell.org/D3029