Allow arguments in response file

There are pretty strict limitations re. the size of a command on Windows. When running ghc through bash on Windows the total size of the command may not exceed 32798 characters. When running a build with a lot of files, one can easily run into this:

bash: ghc.exe: Argument list too long

The maximum length of this string is 32,768 characters, including the Unicode terminating null character. If lpApplicationName is NULL, the module name portion of lpCommandLine is limited to MAX_PATH characters.

from CreateProcessA

It would be great for GHC to allow passing command line arguments through files.

CC @ndmitchell