unified: More $children fixes

Some nodes with a single child (arguably redundant to do, but I think
it's nice to have the types be consistent), and also an instance of
ensuring that all branches of a `choice` expose consistent field names.

unified/extractor/tree-sitter-swift/grammar.js

@@ -452,7 +452,7 @@ module.exports = grammar({
           optional(sep1Opt(field("element", $.tuple_type_item), ",")),
           ")"
         ),
-        alias($._parenthesized_type, $.tuple_type_item)
+        field("element", alias($._parenthesized_type, $.tuple_type_item))
       ),
     tuple_type_item: ($) =>
       prec(
@@ -791,13 +791,13 @@ module.exports = grammar({
       ),
     value_argument_label: ($) =>
       prec.left(
-        choice(
+        field("name", choice(
           $.simple_identifier,
           // We don't rely on $._contextual_simple_identifier here because
           // these don't usually fall into that category.
           alias("if", $.simple_identifier),
           alias("switch", $.simple_identifier)
-        )
+        ))
       ),
     value_argument: ($) =>
       prec.left(
@@ -1094,7 +1094,7 @@ module.exports = grammar({
         $.statements,
         optional("fallthrough")
       ),
-    switch_pattern: ($) => alias($._binding_pattern_with_expr, $.pattern),
+    switch_pattern: ($) => field("pattern", alias($._binding_pattern_with_expr, $.pattern)),
     do_statement: ($) =>
       prec.right(PRECS["do"], seq("do", $._block, repeat(field("catch", $.catch_block)))),
     catch_block: ($) =>

unified/extractor/tree-sitter-swift/node-types.yml

@@ -559,7 +559,7 @@ named:
   switch_entry:
     $children+: [default_keyword, expression, modifiers, statements, switch_pattern, where_keyword]
   switch_pattern:
-    $children: pattern
+    pattern: pattern
   switch_statement:
     entry*: switch_entry
     expr: expression
@@ -579,7 +579,6 @@ named:
     name*: simple_identifier
     value+: expression
   tuple_type:
-    $children?: tuple_type_item
     element*: tuple_type_item
   tuple_type_item:
     $children?: [dictionary_type, existential_type, opaque_type, wildcard_pattern]
@@ -627,7 +626,7 @@ named:
     type_modifiers?: type_modifiers
     value?: expression
   value_argument_label:
-    $children: simple_identifier
+    name: simple_identifier
   value_arguments:
     argument*: value_argument
   value_binding_pattern: