Simple tests for @_package attribute

Author: stevapple

Tests/SwiftParserTest/AttributeTests.swift

@@ -540,4 +540,9 @@ final class AttributeTests: XCTestCase {
     AssertParse("func takeRepeater(_ f: @MainActor @Sendable @escaping () -> Int) {}")
     AssertParse("takeRepesater { @MainActor @Sendable () -> Int in 0 }")
   }
+
+  func testPackageAttribute() {
+    AssertParse(#"@_package(path: "../my-package") import A"#)
+    AssertParse(#"@_package(url: "https://example.com/package.git", from: "0.0.1") @_exported import A"#)
+  }
 }

Tests/SwiftSyntaxBuilderTest/ImportTests.swift

@@ -26,4 +26,15 @@ final class ImportTests: XCTestCase {
 
     AssertBuildResult(importDecl, "␣import SwiftSyntax")
   }
+
+  func testPackageAttribute() {
+    let builder = ImportDeclSyntax("""
+      @_package(url: "https://github.com/apple/swift-log.git", "1.0.0"..<"2.0.0")
+      import Logging
+      """)
+    AssertBuildResult(builder, """
+      @_package(url: "https://github.com/apple/swift-log.git", "1.0.0" ..< "2.0.0")
+      import Logging
+      """)
+  }
 }