[Civl] ABD protocol (#1020)

This PR provides a verified construction of the ABD protocol [1] in
Civl.

[1] Hagit Attiya, Amotz Bar-Noy, and Danny Dolev. Sharing Memory
Robustly in Message-passing Systems. J. ACM 42, 1 (1995), 124–142.

---------

Co-authored-by: Namratha <[email protected]>

Author: shazqadeer

Source/Core/AST/Commands/AbsyCmd.cs

@@ -1489,11 +1489,16 @@ protected override Cmd ComputeDesugaring(PrintOptions options)
 
     public override void Resolve(ResolutionContext rc)
     {
+      var errorCount = rc.ErrorCount;
       (this as ICarriesAttributes).ResolveAttributes(rc);
       foreach (CallCmd callCmd in CallCmds)
       {
         callCmd.Resolve(rc);
       }
+      if (errorCount > rc.ErrorCount)
+      {
+        return;
+      }
 
       HashSet<Variable> parallelCallLhss = new HashSet<Variable>();
       Dictionary<Variable, List<CallCmd>> inputVariables = new Dictionary<Variable, List<CallCmd>>();