update panicking() docs for panic=abort

[biscuitrescue]

fixes #151458

The documentation for std::thread::panicking() has not been changed since v1.0, even though panic hooks were added in v1.10.
Current documentation is misleading for panic=abort

panicking() can return true in 2 different cases:

1. Thread unwinds due to panic
2. Panic hook is executing with panic=abort

r? @SpriteOvO

[SpriteOvO]

Thank you!

Not sure if I have r+ permission for this repo, let me try it...

@bors r+ rollup

View changes since this review

[rust-bors]

@SpriteOvO: 🔑 Insufficient privileges: not in review users

[SpriteOvO]

@rustbot reroll

[SpriteOvO]

Suggested change

	/// | BSD except OpenBSD | [clock_nanosleep] (Monotonic Clock) |
	/// | BSD except OpenBSD | [clock_nanosleep] (Monotonic Clock) |

Before merging, perhaps you'd like to fix this very very very minor nitpick 😇 -- aligning the table's divider.

[biscuitrescue]

done and pushed.

[tgross35]

“panicking” -> “is panicking”

[tgross35]

Perhaps this could be rephrased as

… unwinding due to a panic or executing a panic hook. The latter case will still happen when panic=abort is set.

Since this returns true during panic hooks even when unwinding, right?

Also grammar nits on the current version: “due to a panic”, “and the program”, and missing period at the end of the sentence.

[biscuitrescue]

changed. also edited the underlying system calls table to match case and removed the trailing ] because it was sticking out to me

[rustbot]

Reminder, once the PR becomes ready for a review, use @rustbot ready.

[biscuitrescue]

@rustbot ready

[tgross35]

This returns true when the thread is either unwinding due to a panic, or when it is executing a panic hook. Note that the latter case ...

Minor rewording suggestion to move the "note" bit to the second sentence since it's more of a note, and slightly smooth out the first sentence.

Please squash commits after this then LGTM, thanks for the additional fixes