[Bug other/70268] add option -ffile-prefix-map to map one directory name (old) to another (new) in __FILE__, __BASE_FILE__and __builtin_FILE()

[hongxu.jia at windriver dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70268

--- Comment #4 from hongxu jia <hongxu.jia at windriver dot com> ---
Created attachment 37995
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=37995&action=edit
Implement patch