[manual_let_else]: only omit block if span is from same ctxt

[y21]

Fixes #11579.

The lint already had logic for omitting a block in else if a block is already present, however this didn't handle the case where the block is from a different expansion/syntax context. E.g.

macro_rules! panic_in_block {
  () => { { panic!() } }
}

let _ = match Some(1) {
  Some(v) => v,
  _ => panic_in_block!()
};

It would see this in its expanded form as _ => { panic!() } and think it doesn't have to include a block in its suggestion because it is already there, however that's not true if it's from a different expansion like in this case.

changelog: [manual_let_else]: only omit block in suggestion if the block is from the same expansion

[rustbot]

r? @Jarcho

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[Jarcho]

snippet_with_context already returns whether the snippet is a macro call or not. That should be used instead.

[y21]

Nice, that's even better.

[Jarcho]

Thank you. @bors r+

[bors]

📌 Commit 2d20179 has been approved by Jarcho

It is now in the queue for this repository.

[bors]

⌛ Testing commit 2d20179 with merge b00236d...

[bors]

☀️ Test successful - checks-action_dev_test, checks-action_remark_test, checks-action_test
Approved by: Jarcho
Pushing b00236d to master...