Parsing multiple declarations with conflicting Checked C specifiers w…

…ill throw an error now.

Task: Adding support for polymorphic bounds safe interface functions.
Pending:
1. Parse calls from unchecked scope where type variables may not be substituted with a call site provided type (Apply default type which is "void")
2. Add tests
3. Fix Checked C specifications to reflect the modified syntax for interface type generic functions

lib/Sema/SemaDecl.cpp

@@ -3415,6 +3415,14 @@ bool Sema::MergeFunctionDecl(FunctionDecl *New, NamedDecl *&OldD,
       New->setParams(Params);
     }
 
+    if((New->isItypeGenericFunction() && Old->isGenericFunction())
+        || (New->isGenericFunction() && Old->isItypeGenericFunction()))
+    {
+      Diag(New->getLocation(), diag::err_conflicting_function_specifiers)
+            << New->getDeclName() << "_Itype_for_any" << "_For_any";
+      return true;
+    }
+
     return MergeCompatibleFunctionDecls(New, Old, S, MergeTypeWithOld);
   }