Optimize compile script on MSYS. * lib/compile (func_file_conv): Add new argument 'lazy' which takes an optional list of conversion types where the requested conversion isn't needed. (func_cl_wrapper): Take advantage of the above for cases where MSYS is doing the conversion for us. Suggested by Ralf Wildenhues. Signed-off-by: Peter Rosin <peda@lysator.liu.se>