Fixed regression with optional argument macros and lambdas.

test/unit/regression/lambda_in_macro.c3

@@ -0,0 +1,23 @@
+module lambda;
+
+macro @test(int $xd = ...)
+{
+	return fn int() {
+		static int tx = 0;
+		$if $defined($xd):
+			return $xd + tx++;
+		$else
+			return 0;
+		$endif
+	};
+}
+
+fn void test_lambda_in_macro() @test
+{
+	assert(@test(2)() == 2);
+	assert(@test(2)() == 3);
+	assert(@test(2)() == 4);
+	assert(@test(2)() == 5);
+	assert(@test(4)() == 4);
+	assert(@test()() == 0);
+}