added the test for the #307

Author: dadhi

test/FastExpressionCompiler.IssueTests/Issue307_Switch_with_fall_through_throws_InvalidProgramException.cs

@@ -0,0 +1,56 @@
+using NUnit.Framework;
+using System;
+using System.Linq;
+using System.Collections.Generic;
+#if LIGHT_EXPRESSION
+using static FastExpressionCompiler.LightExpression.Expression;
+namespace FastExpressionCompiler.LightExpression.IssueTests
+#else
+using static System.Linq.Expressions.Expression;
+namespace FastExpressionCompiler.IssueTests
+#endif
+{
+    [TestFixture]
+    public class Issue307_Switch_with_fall_through_throws_InvalidProgramException : ITest
+    {
+        public int Run()
+        {
+            Test1();
+            return 1;
+        }
+
+        // [Test]
+        public void Test1()
+        {
+            var param = Parameter(typeof(int), "p");
+            var label = Label(typeof(string));
+
+            var switchStatement = Switch(
+                typeof(void),
+                param,
+                Return(label, Constant("bar")),
+                null,
+                SwitchCase(Return(label, Constant("foo")), Constant(1), Constant(2)));
+
+            var lambda = Lambda<Func<int, string>>(
+                Block(
+                    switchStatement,
+                    Label(label, Constant(string.Empty))), 
+                param);
+
+            lambda.PrintCSharp();
+
+            var compiled = lambda.CompileSys();
+            compiled.PrintIL();
+
+            var res = compiled(1);
+            Assert.AreEqual("foo", res);
+
+            var compiledFast = lambda.CompileFast();
+            compiledFast.PrintIL();
+
+            var resFast = compiledFast(1);
+            Assert.AreEqual("foo", resFast);
+        }
+    }
+}