Re-add check for whitespace after newlines to preserve block comments in AttributeRemover

Also, added a test case that failed before this fix.

Author: gohanlon

Sources/SwiftSyntaxMacroExpansion/MacroSystem.swift

@@ -399,6 +399,7 @@ private class AttributeRemover: SyntaxRewriter {
       if attributesToRemove.contains(attribute) {
         var leadingTrivia = attribute.leadingTrivia
         if let lastNewline = leadingTrivia.pieces.lastIndex(where: \.isNewline),
+          leadingTrivia.pieces[lastNewline...].allSatisfy(\.isWhitespace),
           attribute.trailingTrivia.isEmpty,
           let nextToken = attribute.nextToken(viewMode: .sourceAccurate),
           !nextToken.leadingTrivia.isEmpty

Tests/SwiftSyntaxMacroExpansionTest/AttributeRemoverTests.swift

@@ -196,6 +196,22 @@ final class AttributeRemoverTests: XCTestCase {
     )
   }
 
+  func testAttributeNewlineBlockCommentEmpty() {
+    assertMacroExpansion(
+      """
+      @State
+      /*doc comment*/@Test
+      var x: Int
+      """,
+      expandedSource: """
+        @State
+        /*doc comment*/
+        var x: Int
+        """,
+      macros: ["Test": NoOpPeerMacro.self]
+    )
+  }
+
   func testEmptyBlockCommentEmpty() {
     assertMacroExpansion(
       """