1793: Fix outer doc-comments of `macro_rules` r=matklad a=uHOOCCOOHu
Document comments of `macro_rules!` is currently parsed outside the `MACRO_CALL` node,
which makes `DocCommentsOwner::doc_comments()` always empty.
For the input:
```rust
/// Some docs
macro_rules! foo {
() => {};
}
```
Current parsing tree is:
```
SOURCE_FILE
COMMENT // <- This should be children of MACRO_CALL
WHITESPACE
MACRO_CALL
PATH
<...omitted...>
```
It should be:
```
SOURCE_FILE
MACRO_CALL
COMMENT
WHITESPACE
PATH
<...omitted...>
```
Co-authored-by: uHOOCCOOHu <hooccooh1896@gmail.com>
734a43e95a