[New msys2-runtime-package version] msys2-runtime: restore msys-2.0.dbg

[github-actions[bot]]

msys2-runtime: restore msys-2.0.dbg

Replicate the objcopy commands that used to work in msys2-runtime build
process.

also, don't strip msys2-runtime-devel.  makepkg's strip mechanism thinks
split debug files are binaries that need to be stripped, and debug files
with the debug info stripped are pretty useless.  msys2/msys2-pacman#52

Fixes #4595

https://github.com/msys2/MSYS2-packages/commit/fca6e3f5d082bd426a2c94d78b7c914ead538e92

[dscho]

I don't think that we need this. When we need to debug MSYS2 runtime issues, we need to build manually anyway.