This patch improves the error message when an invalid option is
detected, by also printing the option that actually caused the error.
For instance, from GDB:
(gdb) target sim --hello
Invalid option: --hello
Usage:
[...]
We also added the usage after an invalid long-name option (Eg: --hello)
to be in line with what's being done for all other invalid options
being detected.
sim/ppc/ChangeLog:
* psim.c (psim_options): Add option that cause the error
in invalid-option error messages. Print the usage when
detecting an invalid long-name option.
11eef9ed35