[Debug] Remove temp workaround in DebugDescriptionMacro (#70746)

This workaround is no longer needed, as of #70435.

Author: kastiglione

lib/Macros/Sources/SwiftMacros/DebugDescriptionMacro.swift

@@ -13,7 +13,6 @@
 import SwiftSyntax
 import SwiftSyntaxMacros
 import SwiftDiagnostics
-import _StringProcessing // for String.contains(_:)
 
 public enum DebugDescriptionMacro {}
 public enum _DebugDescriptionPropertyMacro {}
@@ -51,18 +50,6 @@ extension DebugDescriptionMacro: MemberAttributeMacro {
       return []
     }
 
-    // Expansion is performed multiple times. Exit early to avoid emitting duplicate macros,
-    // which leads to duplicate symbol errors. To distinguish been invocations, inspect the
-    // current mangled name. This ignores the invocation that adds a "__vg" suffix to the member
-    // name, ex "description__vg". See https://github.com/apple/swift/pull/65559.
-    let mangledName = context.makeUniqueName("").text
-    let substring = "\(propertyName)__vg"
-    // Ex: "15description__vg"
-    let runlengthSubstring = "\(substring.count)\(substring)"
-    guard !mangledName.hasSubstring(runlengthSubstring) else {
-      return []
-    }
-
     var properties: [String: PatternBindingSyntax] = [:]
     for member in declaration.memberBlock.members {
       for binding in member.decl.as(VariableDeclSyntax.self)?.bindings ?? [] {
@@ -501,18 +488,3 @@ extension Collection {
     count == 1 ? first : nil
   }
 }
-
-extension String {
-  fileprivate func hasSubstring(_ substring: String) -> Bool {
-    if #available(macOS 13, *) {
-      return self.contains(substring)
-    }
-
-    for index in self.indices {
-      if self.suffix(from: index).hasPrefix(substring) {
-        return true
-      }
-    }
-    return false
-  }
-}