Add release notes and format

Author: Azoy

Release Notes/603.md

@@ -0,0 +1,24 @@
+# Swift Syntax 603 Release Notes
+
+## New APIs
+
+- `GenericParameterSyntax` now has a new `initializer` property.
+  - Description: Generic parameters can now optionally be passed a default type. The `initializer` is a `TypeInitializerSyntax` that captures both the `=` and the parsed `TypeSyntax`.
+  - Pull Request: https://github.com/swiftlang/swift-syntax/pull/3152
+
+## API Behavior Changes
+
+## Deprecations
+
+## API-Incompatible Changes
+
+## Template
+
+- *Affected API or two word description*
+  - Description: *A 1-2 sentence description of the new/modified API*
+  - Issue: *If an issue exists for this change, a link to the issue*
+  - Pull Request: *Link to the pull request(s) that introduces this change*
+  - Migration steps: Steps that adopters of swift-syntax should take to move to the new API (required for deprecations and API-incompatible changes).
+  - Notes: *In case of deprecations or API-incompatible changes, the reason why this change was made and the suggested alternative*
+
+*Insert entries in chronological order, with newer entries at the bottom*

Sources/SwiftParser/Declarations.swift

@@ -680,8 +680,9 @@ extension Parser {
         // type parameters, not parameter packs or value generics yet.
         let defaultType: RawTypeInitializerClauseSyntax?
         if self.experimentalFeatures.contains(.defaultGenerics),
-           specifier == nil,
-           let equal = self.consume(if: .equal) {
+          specifier == nil,
+          let equal = self.consume(if: .equal)
+        {
           let type = self.parseType()
           defaultType = RawTypeInitializerClauseSyntax(
             equal: equal,

Tests/SwiftParserTest/DefaultGenericsTest.swift

@@ -76,7 +76,7 @@ final class DefaultGenericsTest: ParserTestCase {
         ),
         DiagnosticSpec(
           message: "unexpected code '= Int>' in struct"
-        )
+        ),
       ],
       fixedSource: """
         struct A<each T> = Int> {}
@@ -98,7 +98,7 @@ final class DefaultGenericsTest: ParserTestCase {
         ),
         DiagnosticSpec(
           message: "unexpected code '= Int>' in struct"
-        )
+        ),
       ],
       fixedSource: """
         struct A<let n: Int> = Int> {}