crt: Ignore CR at EOL when generating DEF files

On Windows, a native C preprocessor outputs CRLF line endings. When using a
native toolchain in Cygwin, the Cygwin sed takes only LF line endings, so these
regular expressions fail to match stdcall suffixes for non-i686 targets.

This commit addresses the issue by allowing these regular expressions to match
an optional CR at EOL.

Reference: https://sourceforge.net/p/mingw-w64/mailman/message/59337512/
Reported-by: Liaiss Merzougue <merzougue@adacore.com>
Signed-off-by: LIU Hao <lh_mouse@126.com>