Support sending keyword

https://github.com/swiftlang/swift-evolution/blob/main/proposals/0430-transferring-parameters-and-results.md

Author: taku0

swift-mode-font-lock.el

@@ -524,7 +524,7 @@ Return nil otherwise."
     "import" "init" "inout" "internal" "let" "open" "operator" "package"
     "private" "protocol" "public" "any" "some" "static" "struct" "subscript"
     "typealias" "var" "actor" "nonisolated" "isolated" "distributed"
-    "borrowing" "consuming" "macro")
+    "borrowing" "consuming" "sending" "macro")
   "Keywords used in declarations.")
 
 (defconst swift-mode:statement-keywords

swift-mode-lexer.el

@@ -610,10 +610,10 @@ return non-nil."
        ;; Suppress implicit semicolon around keywords that cannot start or end
        ;; statements.
        (member (swift-mode:token:text previous-token)
-               '("any" "some" "inout" "borrowing" "consuming" "in" "where"
-                 "isolated" "each"))
+               '("any" "some" "inout" "borrowing" "consuming" "sending" "in"
+                 "where" "isolated" "each"))
        (member (swift-mode:token:text next-token)
-               '("any" "some" "inout" "borrowing" "consuming" "throws"
+               '("any" "some" "inout" "borrowing" "consuming" "sending" "throws"
                  "rethrows" "in" "where" "isolated" "each"))
 
        ;; Suppress implicit semicolon between throws and open parenthesis.

test/swift-files/indent/declarations.swift

@@ -390,12 +390,14 @@ private
     z,
     w:
       consuming
+      sending
       Int
       ...
   )
   async
   throws
   ->
+  sending
   [A]
   where
     A:

test/swift-files/indent/identifiers.swift

@@ -73,6 +73,9 @@ func foo() {
     foo(
       consuming: 1
     )
+    foo(
+      sending: 1
+    )
     foo(
       internal: 1
     )