add record types and tuple types to symbolic package

[Stephen Siegel]

CVC3 supports record types and tuple types. Now we need to add these to the symbolic package. There should be a method to create such a type like

SymType newRecordType(String name, String[] fieldNames, SymType[] fieldTypes);
SymType newTypleType(String name, String[] fieldTypes);

A tuple type is just the special case of record type, where the fields are just named 0, 1, 2, ....

Then there must be methods to

1. create a new SymExpression of a given record type, given the field values
2. read a field from a record
3. modify a field in a record.

Ditto for tuples.

This is similar in many ways to the way arrays are dealt with.

The following is an example of using the CVC3 interactive to create a record type:

Reference : TYPE = [# pid         : INT,
                      stackIndex  : INT,
                      id          : INT,
                      numLinks    : INT,
                      links       : ARRAY INT OF INT #];

a,a1 : ARRAY INT OF INT;
ASSERT a1 = a WITH [0] := 3, [1]:=5;
r1 : Reference = (# pid:=2, stackIndex:=-1, id:=3, numLinks:=2, links:=a1 #);
TRANSFORM r1;

The CVC3 manual has a detailed description of record types. Here is a simple example from the manual:

% Record updates

Item: TYPE = [# key: INT, weight: REAL #];

x:  Item = (# key := 23, weight := 43/10 #);

x1: Item = x WITH .weight := 48;