Add init accessors

https://github.com/apple/swift-evolution/blob/main/proposals/0400-init-accessors.md

Author: taku0

swift-mode-beginning-of-defun.el

@@ -24,7 +24,7 @@
 ;; `beginning-of-defun' and `end-of-defun'
 ;;
 ;; A defun is a declaration except local variable, "get", "set", "willSet",
-;; "didSet", or "case" within enum.
+;; "didSet", "case" within enum, or "init" within var.
 ;;
 ;; A defun include modifiers, attributes, and comments on the same line.
 ;;
@@ -1417,7 +1417,8 @@ of ancestors."
                       (when (eq (swift-mode:token:type next-token) 'identifier)
                         next-token))))
             name-tokens)
-        '()))))
+        (swift-mode:backward-sexps-until-open-curly-bracket)
+        (swift-mode:current-defun-name-token-list)))))
 
 (defun swift-mode:current-defun-name-token ()
   "Return the name token of the defun under the point."

test/swift-files/beginning-of-defun/beginning-of-defun.swift

@@ -166,17 +166,17 @@ foo() {
 /*{*/enum Foo<A> where A: B {
     /*{*/case Foo(a: Int)/*}*/
     /*{*/case Bar(b: Int), Baz/*}*/
-    /*{*/case
-      A(
-        b
-          :
-          Int)
-            ,
-      @Foo
+    /*{*/@Foo
       indirect
+        case
+        A(
+          b
+            :
+            Int)
+           ,
         B
-        =
-        0/*}*/
+          =
+          0/*}*/
 
     /*{*/func foo() -> a {
         /*[*/switch this {

test/swift-files/indent/declarations.swift

@@ -220,6 +220,10 @@ class Foo {
     }
 
     var x {
+        init {
+            x = 1
+        }
+
         get {
             1
         }
@@ -230,6 +234,11 @@ class Foo {
     }
 
     var x {
+        init
+        {
+            x = 1
+        }
+
         get
         {
             1
@@ -241,6 +250,37 @@ class Foo {
         }
     }
 
+    var x {
+        init(newValue) {
+            x = 1
+        }
+
+        get {
+            1
+        }
+
+        set(newValue) {
+            foo()
+        }
+    }
+
+    var x {
+        init(newValue)
+        {
+            x = 1
+        }
+
+        get
+        {
+            1
+        }
+
+        set(newValue)
+        {
+            foo()
+        }
+    }
+
     var x {
         get
           async