fix [dbg_macro] FN when dbg is inside some complex macros

[J-ZhengLi]

fixes: #12131

It appears that [root_macro_call_first_node] only detects println! in the following example:

println!("{:?}", dbg!(s));

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changelog: fix [dbg_macro] FN when dbg is inside some complex macros

(re-opening b'cuz bors doesn't like my previous one)

[rustbot]

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[J-ZhengLi]

r? @Jarcho

[J-ZhengLi]

still showing a big red x next to my first commit though, not sure what's happening @Jarcho , I'll try modify that commit message or squash them to see if that go away.

[Jarcho]

Lets try this again. @bors r+

[bors]

📌 Commit fe4e0ac has been approved by Jarcho

It is now in the queue for this repository.

[bors]

⌛ Testing commit fe4e0ac with merge 12ecaa8...

[bors]

☀️ Test successful - checks-action_dev_test, checks-action_remark_test, checks-action_test
Approved by: Jarcho
Pushing 12ecaa8 to master...