compiler: support calling function literals

pkg/compiler/lambda_test.go

@@ -13,3 +13,16 @@ func TestFuncLiteral(t *testing.T) {
 	}`
 	eval(t, src, big.NewInt(5))
 }
+
+func TestCallInPlace(t *testing.T) {
+	src := `package foo
+	var a int = 1
+	func Main() int {
+		func() {
+			a += 10
+		}()
+		a += 100
+		return a
+	}`
+	eval(t, src, big.NewInt(111))
+}