Rename `optin_builtin_traits` to `auto_traits`

They were originally called "opt-in, built-in traits" (OIBITs), but
people realized that the name was too confusing and a mouthful, and so
they were renamed to just "auto traits". The feature flag's name wasn't
updated, though, so that's what this PR does.

There are some other spots in the compiler that still refer to OIBITs,
but I don't think changing those now is worth it since they are internal
and not particularly relevant to this PR.

Also see <https://rust-lang.zulipchat.com/#narrow/stream/131828-t-compiler/topic/opt-in.2C.20built-in.20traits.20(auto.20traits).20feature.20name>.

7 files changed, 7 insertions, 7 deletions

diff --git a/src/test/rustdoc/auto-traits.rs b/src/test/rustdoc/auto-traits.rs
index a1fa611994f..93d4bf2f656 100644
--- a/src/test/rustdoc/auto-traits.rs
+++ b/src/test/rustdoc/auto-traits.rs
@@ -1,6 +1,6 @@
 // aux-build:auto-traits.rs
 
-#![feature(optin_builtin_traits)]
+#![feature(auto_traits)]
 
 #![crate_name = "foo"]
 
diff --git a/src/test/rustdoc/auto_aliases.rs b/src/test/rustdoc/auto_aliases.rs
index 7b52a69f560..b8f3527510c 100644
--- a/src/test/rustdoc/auto_aliases.rs
+++ b/src/test/rustdoc/auto_aliases.rs
@@ -1,4 +1,4 @@
-#![feature(optin_builtin_traits)]
+#![feature(auto_traits)]
 
 // @has auto_aliases/trait.Bar.html '//h3[@aliases="auto_aliases::Foo"]' 'impl Bar for Foo'
 pub struct Foo;
diff --git a/src/test/rustdoc/auxiliary/auto-traits.rs b/src/test/rustdoc/auxiliary/auto-traits.rs
index f5221061388..84976c73bee 100644
--- a/src/test/rustdoc/auxiliary/auto-traits.rs
+++ b/src/test/rustdoc/auxiliary/auto-traits.rs
@@ -1,3 +1,3 @@
-#![feature(optin_builtin_traits)]
+#![feature(auto_traits)]
 
 pub unsafe auto trait Bar {}
diff --git a/src/test/rustdoc/auxiliary/rustdoc-default-impl.rs b/src/test/rustdoc/auxiliary/rustdoc-default-impl.rs
index 36e2821c5a8..032db3b25e6 100644
--- a/src/test/rustdoc/auxiliary/rustdoc-default-impl.rs
+++ b/src/test/rustdoc/auxiliary/rustdoc-default-impl.rs
@@ -1,4 +1,4 @@
-#![feature(optin_builtin_traits)]
+#![feature(auto_traits)]
 
 pub mod bar {
     use std::marker;
diff --git a/src/test/rustdoc/auxiliary/rustdoc-impl-parts-crosscrate.rs b/src/test/rustdoc/auxiliary/rustdoc-impl-parts-crosscrate.rs
index 869aebc774a..46adf2e6bc0 100644
--- a/src/test/rustdoc/auxiliary/rustdoc-impl-parts-crosscrate.rs
+++ b/src/test/rustdoc/auxiliary/rustdoc-impl-parts-crosscrate.rs
@@ -1,3 +1,3 @@
-#![feature(optin_builtin_traits)]
+#![feature(auto_traits)]
 
 pub auto trait AnOibit {}
diff --git a/src/test/rustdoc/impl-parts.rs b/src/test/rustdoc/impl-parts.rs
index 68baca9a04e..5e9e84a554b 100644
--- a/src/test/rustdoc/impl-parts.rs
+++ b/src/test/rustdoc/impl-parts.rs
@@ -1,5 +1,5 @@
 #![feature(negative_impls)]
-#![feature(optin_builtin_traits)]
+#![feature(auto_traits)]
 
 pub auto trait AnOibit {}
 
diff --git a/src/test/rustdoc/synthetic_auto/crate-local.rs b/src/test/rustdoc/synthetic_auto/crate-local.rs
index 341dd572f81..3346ac05ffe 100644
--- a/src/test/rustdoc/synthetic_auto/crate-local.rs
+++ b/src/test/rustdoc/synthetic_auto/crate-local.rs
@@ -1,4 +1,4 @@
-#![feature(optin_builtin_traits)]
+#![feature(auto_traits)]
 
 pub auto trait Banana {}