[RFA] Change auto_load_objfile_script_1 to use std::string

[Simon Marchi]

On 2018-03-17 11:46 AM, Tom Tromey wrote:
> This replaces some manual string manipulation in
> auto_load_objfile_script_1 with std::string, simplifying the code and
> allowing the removal of some cleanups.

LGTM.

Simon