Rollup merge of rust-lang#39761 - est31:master, r=aturon

Stabilize field init shorthand

Closes rust-lang#37340.

~Still blocked by the documentation issue rust-lang#38830.~ EDIT: seems that all parts required for stabilisation are fixed, so its not blocked.

Author: frewsxcv

src/doc/book/src/structs.md

@@ -122,8 +122,6 @@ fields of the data structure are initialized with variables of the same
 names as the fields.
 
 ```
-#![feature(field_init_shorthand)]
-
 #[derive(Debug)]
 struct Person<'a> {
     name: &'a str,

src/doc/reference.md

@@ -2825,7 +2825,6 @@ This allows a compact syntax with less duplication.
 Example:
 
 ```
-# #![feature(field_init_shorthand)]
 # struct Point3d { x: i32, y: i32, z: i32 }
 # let x = 0;
 # let y_value = 0;

src/librustc/lib.rs

@@ -29,7 +29,7 @@
 #![feature(conservative_impl_trait)]
 #![feature(const_fn)]
 #![feature(core_intrinsics)]
-#![feature(field_init_shorthand)]
+#![cfg_attr(stage0,feature(field_init_shorthand))]
 #![feature(i128_type)]
 #![feature(libc)]
 #![feature(loop_break_value)]

src/librustc_incremental/lib.rs

@@ -24,7 +24,7 @@
 #![feature(rand)]
 #![feature(core_intrinsics)]
 #![feature(conservative_impl_trait)]
-#![feature(field_init_shorthand)]
+#![cfg_attr(stage0,feature(field_init_shorthand))]
 #![feature(pub_restricted)]
 
 extern crate graphviz;

src/librustc_typeck/lib.rs

@@ -77,7 +77,7 @@ This API is completely unstable and subject to change.
 #![feature(box_patterns)]
 #![feature(box_syntax)]
 #![feature(conservative_impl_trait)]
-#![feature(field_init_shorthand)]
+#![cfg_attr(stage0,feature(field_init_shorthand))]
 #![feature(loop_break_value)]
 #![feature(quote)]
 #![feature(rustc_diagnostic_macros)]

src/libsyntax/feature_gate.rs

@@ -288,9 +288,6 @@ declare_features! (
     // Allows attributes on lifetime/type formal parameters in generics (RFC 1327)
     (active, generic_param_attrs, "1.11.0", Some(34761)),
 
-    // Allows field shorthands (`x` meaning `x: x`) in struct literal expressions.
-    (active, field_init_shorthand, "1.14.0", Some(37340)),
-
     // The #![windows_subsystem] attribute
     (active, windows_subsystem, "1.14.0", Some(37499)),
 
@@ -385,6 +382,8 @@ declare_features! (
     (accepted, more_struct_aliases, "1.16.0", Some(37544)),
     // elide `'static` lifetimes in `static`s and `const`s
     (accepted, static_in_const, "1.17.0", Some(35897)),
+    // Allows field shorthands (`x` meaning `x: x`) in struct literal expressions.
+    (accepted, field_init_shorthand, "1.17.0", Some(37340)),
 );
 // (changing above list without updating src/doc/reference.md makes @cmr sad)
 
@@ -1233,10 +1232,6 @@ impl<'a> Visitor<'a> for PostExpansionVisitor<'a> {
             }
             ast::ExprKind::Struct(_, ref fields, _) => {
                 for field in fields {
-                    if field.is_shorthand {
-                        gate_feature_post!(&self, field_init_shorthand, field.span,
-                                           "struct field shorthands are unstable");
-                    }
                     if starts_with_digit(&field.ident.node.name.as_str()) {
                         gate_feature_post!(&self, relaxed_adts,
                                           field.span,

src/test/compile-fail/feature-gate-field-init-shorthand.rs

@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(field_init_shorthand)]
-
 struct Foo {
     x: i32,
     y: i32

src/test/compile-fail/struct-fields-shorthand-unresolved.rs

@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(field_init_shorthand)]
-
 struct Foo {
     x: i32,
     y: i32

src/test/compile-fail/struct-fields-shorthand.rs

@@ -10,8 +10,6 @@
 
 // compile-flags: -Z parse-only
 
-#![feature(field_init_shorthand)]
-
 struct Rgb(u8, u8, u8);
 
 fn main() {

src/test/parse-fail/struct-field-numeric-shorthand.rs

@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(field_init_shorthand)]
-
 struct Foo {
     x: i32,
     y: bool,