* In checkFormalActualBaseTypesMatch() and checkFormalActualTypesMatch(),
ensure with INT_FATAL that whenever the actual is 'nil', the formal
is of a (Chapel) class type.
* In createTaskFunctions(), strengthen an assertion.
* In CyclicDist.chpl, do not set the pid upon 'new CyclicArr(...)'.
Rationale: 'pid' should be set when the object is privatized using
_newPrivatizedClass. Setting 'pid' to that of another already-
privatized object breaks some unspoken invariants/assumptions.
* In ChapelArray.chpl, replace _isPrivatized(a._value) with
_isPrivatized(a._valueType), where 'a' is a _distribution.
This is for consistency with the other uses of _isPrivatized.
Also, for privatized distributions a._value-the-accessor is an int,
so I am unclear how it worked at all before this change.