small abstractions: func_source, func_execute_cmds

[Ralf Wildenhues]

OK to both patches for HEAD (-33 lines, -66 lines, while investigating
unrelated bugs)?

Cheers,
Ralf

        * config/ltmain.m4sh (func_source): New function.
        (func_mode_execute, func_mode_install, func_mode_link): Use it.

        * config/ltmain.m4sh (func_execute_cmds): New function.
        (func_mode_finish, func_mode_install, func_mode_link)
        (func_mode_uninstall): Use it.

ralf-HEAD-func_source
Description: Text document

ralf-HEAD-func_execute_cmds
Description: Text document