failures (1):
    regression::issue2565::simple_variant

Currently panics in derive:

error: proc-macro derive panicked
    --> test_suite\tests\test_annotations.rs:2386:25
     |
2386 |     #[derive(Serialize, Deserialize, PartialEq, Debug)]
     |                         ^^^^^^^^^^^
     |
     = help: message: assertion failed: !cattrs.has_flatten()

error: proc-macro derive panicked
  --> test_suite\tests\regression\issue1904.rs:57:10
   |
57 | #[derive(Deserialize)]
   |          ^^^^^^^^^^^
   |
   = help: message: assertion failed: !cattrs.has_flatten()

error: proc-macro derive panicked
  --> test_suite\tests\regression\issue1904.rs:47:10
   |
47 | #[derive(Deserialize)]
   |          ^^^^^^^^^^^
   |
   = help: message: assertion failed: !cattrs.has_flatten()

error: proc-macro derive panicked
  --> test_suite\tests\regression\issue1904.rs:37:10
   |
37 | #[derive(Deserialize)]
   |          ^^^^^^^^^^^
   |
   = help: message: assertion failed: !cattrs.has_flatten()

error: proc-macro derive panicked
  --> test_suite\tests\regression\issue1904.rs:27:10
   |
27 | #[derive(Deserialize)]
   |          ^^^^^^^^^^^
   |
   = help: message: assertion failed: !cattrs.has_flatten()

error: proc-macro derive panicked
  --> test_suite\tests\regression\issue1904.rs:16:10
   |
16 | #[derive(Deserialize)]
   |          ^^^^^^^^^^^
   |
   = help: message: assertion failed: !cattrs.has_flatten()

error: proc-macro derive panicked
 --> test_suite\tests\regression\issue1904.rs:7:10
  |
7 | #[derive(Deserialize)]
  |          ^^^^^^^^^^^
  |
  = help: message: assertion failed: !cattrs.has_flatten()

- Fix incorrect deserialization of variants that doesn't contain flatten field when other contains
- Fix a panic when deriving `Deserialize` for an enum with tuple and struct with flatten field

Fixes (2):
    regression::issue2565::simple_variant
    regression::issue1904 (compilation)