Add lambdas.

test/test_suite/lambda/lambda_in_macro.c3t

@@ -0,0 +1,45 @@
+// #target: macos-x64
+module test;
+import std::io;
+
+define Callback1 = fn double(double x);
+define Callback2 = fn int(int y);
+
+macro test2(y)
+{
+	var $Type = $typeof(y);
+	return fn $Type($typeof(y) x) { return x * x; };
+}
+
+macro test($Type)
+{
+	$Type z = fn (x) { return x * x; };
+	return z;
+}
+
+fn void main()
+{
+	io::printfn("val: %d", test(Callback2)(3));
+	io::printfn("val: %s", test(Callback1)(3.3));
+	io::printfn("val: %s", test(Callback1)(3.3));
+	io::printfn("val: %d", test2(1)(3));
+	io::printfn("val: %d", test2(1)(3));
+	io::printfn("val: %s", test2(1.0)(3.3));
+}
+
+/* #expect: test.ll
+
+  store ptr @"test_test$lambda1", ptr %z, align 8
+  %1 = call i32 %0(i32 3)
+  store ptr @"test_test$lambda2", ptr %z3, align 8
+  %7 = call double %6(double 3.300000e+00)
+  store ptr @"test_test$lambda2", ptr %z10, align 8
+  %13 = call double %12(double 3.300000e+00)
+  %18 = call i32 @"test_test2$lambda3"(i32 3)
+  %23 = call i32 @"test_test2$lambda3"(i32 3)
+  %28 = call double @"test_test2$lambda4"(double 3.300000e+00)
+
+define internal double @"test_test2$lambda4"(double %0) #0 {
+define internal i32 @"test_test2$lambda3"(i32 %0) #0 {
+define internal double @"test_test$lambda2"(double %0) #0 {
+define internal i32 @"test_test$lambda1"(i32 %0) #0 {