Update msys2_installation.rb #iterate_msys_paths

[dsisnero]

prefer ENV["MSYS2_PATH"] if set for #iterate_msys_paths

[dsisnero]

Can we get this merged?

[larskanis]

Can you tell something about your use case? Why are the current options to find the MSYS2 directory not enough? For instance it's possible to add the MSYS2 directory to the PATH environment variable if it's in a uncommon location. You also can make a link into the ruby directory to the MSYS2 location.
To merge this we also need a test case.

[dsisnero]

I don't want to have MYS2 under PATH environment variable because I don't want to use any of those executables unless I specifically ridk enable - or open amys2 or mingw shell.

I don't default to c:\msys2 because I need to install it on a work computer with limited space in c drive, This computer is locked down for most users so they don't have the capability to create drive junctions , (symlinks) and limited functionality. For me, I install it in a separate usb c drive - e:\msys2 and it is easiest to set an ENVIRONMENT variable for this rather then symlink. I would just tell people who installed ruby open command prompt and type setx MSYS2_PATH e:\msys2 or to whatever drive they have mapped and they won't have to get admin privileges to enable creating symlinks