Functions that appear in continuous assignment expressions and that
have hidden dependencies or side effects need to be re-evaluated
whenever any input to the expression changes. This patch adds support
in the compiler and vvp runtime to enable this. This is currently
activated for any system function call that has no arguments. The
user may also force it to be used for any user function by passing
the option -gstrict-ca-eval to the compiler driver.
This patch also removes the -dautomatic option which was used for
gaining confidence in the code that supports automatic tasks and
functions. It is believed that the testsuite provides reasonable
fault coverage, and further tests can be added if bugs are found.
Put together the infrastructure for elaborating analog statements,
including create the NetAnalogTop objects that hold analog statements
and are in turn held by the design.
While doing this, clean up the various unique initial/always enumerations
to use the ivl_process_type_t type.
In preparation for using the synthesize method to replace the
elaborate_net method of PExpr, rework the interface to the
synthesize() method. This changes no fnctionality, but does set
up the infrastructure for the next step.