[CodeComplete] Query the Solution for contextual type

Instead of querying the ConstraintSystem, query the
Solution instead, as the ConstraintSystem is not
necessarily in the same state as when the solution
was produced.

Author: hamishknight

lib/IDE/TypeCheckCompletionCallback.cpp

@@ -52,8 +52,6 @@ Type swift::ide::getTypeForCompletion(const constraints::Solution &S,
     return nullptr;
   }
 
-  auto &CS = S.getConstraintSystem();
-
   Type Result;
 
   if (isExpr<CodeCompletionExpr>(Node)) {
@@ -62,9 +60,9 @@ Type swift::ide::getTypeForCompletion(const constraints::Solution &S,
     Result = S.getResolvedType(Node);
   }
 
-  if (!Result || Result->is<UnresolvedType>()) {
-    Result = CS.getContextualType(Node, /*forConstraint=*/false);
-  }
+  if (!Result || Result->is<UnresolvedType>())
+    Result = S.getContextualType(Node);
+
   if (Result && Result->is<UnresolvedType>()) {
     Result = Type();
   }