* common.din (__mempcpy): ... to here.
* x86_64.din: Move strtold definition... * common.din: ...to here.
* x86_64.din: New file. * common.din: New file. * cygwin.din: Delete. * cygwin64.din: Delete. * gendef: Rework to take options rather than using positional parameters. Accept multiple files as input.