Auto merge of #110275 - matthiaskrgr:rollup-8ntb3o5, r=matthiaskrgr

Rollup of 6 pull requests

Successful merges:

 - #110072 (Stabilize IsTerminal)
 - #110195 (Erase lifetimes above `ty::INNERMOST` when probing ambiguous types)
 - #110218 (Remove `ToRegionVid`)
 - #110220 (cleanup our region error API)
 - #110234 (Fix btree `CursorMut::insert_after` check)
 - #110262 (Update unwind_safe.rs)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup

Author: bors

src/lib.rs

@@ -7,7 +7,6 @@
 #![feature(yeet_expr)]
 #![feature(nonzero_ops)]
 #![feature(local_key_cell_methods)]
-#![feature(is_terminal)]
 #![feature(round_ties_even)]
 // Configure clippy and other lints
 #![allow(

tests/pass/shims/fs.rs

@@ -3,7 +3,6 @@
 
 #![feature(io_error_more)]
 #![feature(io_error_uncategorized)]
-#![feature(is_terminal)]
 
 use std::collections::HashMap;
 use std::ffi::{c_char, OsString};

tests/pass/shims/io.rs

@@ -1,5 +1,3 @@
-#![feature(is_terminal)]
-
 use std::io::IsTerminal;
 
 fn main() {