This patch addresses a number of issues:
Rewrote the $test$plusargs and $value$plusargs routines to have
better error/warning messages, to support runtime strings, to
correctly load bit based values (truncating, padding, negative
value), added support for the real formats using strtod() and
added "x/X" as an alias for "h/H" to match the other part of
Icarus.
Rewrite the vpip_{bin,oct,hex}_str_to_vec4 routines to ignore
embedded "_" characters. Add support for a negative value and
set the entire value to 'bx if an invalid digit is found. A
warning is printed for this case.
Rewrite vpip_dec_str_to_vec4 to ignore embedded "_" characters,
to support a single "x" or "z" constant and to return 'bx if an
invalid digit is found. A warning is printed for this case.
It simplifies the system task/functions error/warning messages.
It removes the signed flag for the bin and dec string conversions.
This was not being used (was always false) and the new negative
value support makes this obsolete.
Add support for a real variable to handle Bin, Oct, Dec and Hex
strings. They are converted into a vvp_vector4_t which is then
converted to a real value.
Add support for setting a bit based value using a real value.
Removed an unneeded rfp signal in vpip_make_reg()