* source.c: #include gdb_assert.h.

    * source.c: #include gdb_assert.h.
        (substitute_path_rule): New struct.
        (substitute_path_rules): New static global variable.
        (substitute_path_rule_matches): New function.
        (get_substitute_path_rule): New function.
        (rewrite_source_path): New function.
        (find_and_open_source): Add source path rewriting support.
        (strip_trailing_directory_separator): New function.
        (find_substitute_path_rule): New function.
        (add_substitute_path_rule): New function.
        (delete_substitute_path_rule): New function.
        (show_substitute_path_command): New function.
        (unset_substitute_path_command): New function.
        (set_substitute_path_command): New function.
        (_initialize_source): Add new substitute-path commands.
        * Makefile.in (source.o): Add dependency on gdb_assert.h.