Technically the sized function is not currently needed by Icarus since
the SFT file handles this type of information, but lets define this so
that things work correctly if we ever switch to using the standard VPI
interface. Also mark this as a system defined function.
The $ivlh_attribute_event system function helps the Verilog runtime
support <name>'event expressions in VHDL. The vhdlpp generates a
call to $ivlh_attribute_event, which in turn uses callbacks to handle
the support.
This is also the start of the vhdl_sys vpi module. This module should
by included whenever VHDL code is parsed.
Cary R
Stephen Williams