Creates the initial (empty) environment state for a freshly created new.env().
When called from processAssignmentToSymbol, pass sourceInfo so that a
statically-resolved parent argument (stored in the vertex's newEnvParent field)
is honoured. Without sourceInfo (or when no newEnvParent is present), falls back
to the current execution environment as parent.
Creates the initial (empty) environment state for a freshly created
new.env().When called from
processAssignmentToSymbol, passsourceInfoso that a statically-resolvedparentargument (stored in the vertex'snewEnvParentfield) is honoured. WithoutsourceInfo(or when nonewEnvParentis present), falls back to the current execution environment as parent.