Fix warnings in test cases

ICSharpCode.Decompiler.Tests/TestCases/Correctness/Switch.cs

@@ -169,7 +169,9 @@ namespace ICSharpCode.Decompiler.Tests.TestCases.Correctness
 				case false:
 					return bool.FalseString;
 				default:
+#pragma warning disable CS0162
 					return null;
+#pragma warning restore CS0162
 			}
 		}
 

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

@@ -33,6 +33,7 @@ namespace LocalFunctions
 		{
 			public int MixedLocalFunction<T2>() where T2 : ICloneable, IConvertible
 			{
+#pragma warning disable CS0219
 				T2 t2 = default(T2);
 				object z = this;
 				for (int j = 0; j < 10; j++) {
@@ -107,6 +108,7 @@ namespace LocalFunctions
 						return k;
 					}
 				}
+#pragma warning restore CS0219
 			}
 
 			public int MixedLocalFunction2Delegate<T2>() where T2 : ICloneable, IConvertible
@@ -199,6 +201,7 @@ namespace LocalFunctions
 
 			public static void Test_CaptureT<T2>()
 			{
+#pragma warning disable CS0219
 				T2 t2 = default(T2);
 				Method1<int>();
 				void Method1<T3>()
@@ -214,6 +217,7 @@ namespace LocalFunctions
 						t3 = default(T3);
 					}
 				}
+#pragma warning restore CS0219
 			}
 
 			public void TestGenericArgs<T2>() where T2 : List<T2>

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

@@ -47,6 +47,7 @@ namespace ICSharpCode.Decompiler.Tests.TestCases.Pretty
 
 		private void Issue1881()
 		{
+#pragma warning disable CS0219
 			MyEnum enumLocal1 = MyEnum.VALUE1;
 			MyEnum enumLocal2 = (MyEnum)0;
 			enumLocal2 = MyEnum.VALUE1;
@@ -56,6 +57,7 @@ namespace ICSharpCode.Decompiler.Tests.TestCases.Pretty
 			ValueType enumLocal5 = MyEnum.VALUE1;
 			ValueType enumLocal6 = (MyEnum)0;
 			enumLocal6 = MyEnum.VALUE2;
+#pragma warning restore CS0219
 		}
 #endif
 	}