Include "base." qualifier as needed (fixes #1123)

Adds BaseReferenceExpression to ThisReferenceExpression target required checks

ICSharpCode.Decompiler.Tests/TestCases/Pretty/FixProxyCalls.cs

@@ -32,7 +32,7 @@ namespace ICSharpCode.Decompiler.Tests.TestCases.ILPretty
 	{
 		protected internal IEnumerable<string> Test2(string test)
 		{
-			yield return base.Test(test);
+			yield return Test(test);
 		}
 	}
 

ICSharpCode.Decompiler/CSharp/CallBuilder.cs

@@ -210,7 +210,7 @@ namespace ICSharpCode.Decompiler.CSharp
 						if (method.IsStatic)
 							requireTarget = !expressionBuilder.IsCurrentOrContainingType(method.DeclaringTypeDefinition) || method.Name == ".cctor";
 						else
-							requireTarget = !(target.Expression is ThisReferenceExpression) || method.Name == ".ctor";
+							requireTarget = !(target.Expression is ThisReferenceExpression || target.Expression is BaseReferenceExpression) || method.Name == ".ctor";
 					}
 					bool targetCasted = false;
 					bool argumentsCasted = false;

ICSharpCode.Decompiler/CSharp/ExpressionBuilder.cs

@@ -196,7 +196,7 @@ namespace ICSharpCode.Decompiler.CSharp
 		{
 			var target = TranslateTarget(field, targetInstruction, true);
 			bool requireTarget = HidesVariableWithName(field.Name)
-				|| (field.IsStatic ? !IsCurrentOrContainingType(field.DeclaringTypeDefinition) : !(target.Expression is ThisReferenceExpression));
+				|| (field.IsStatic ? !IsCurrentOrContainingType(field.DeclaringTypeDefinition) : !(target.Expression is ThisReferenceExpression || target.Expression is BaseReferenceExpression));
 			bool targetCasted = false;
 			var targetResolveResult = requireTarget ? target.ResolveResult : null;