Stop treating macro declaring init identifier as producing initializers

Unwind a temporary workaround we put into the compiler that treated
the escaped identifier "init" as an initializer in the set of names
introduced by a macro. We've addressed the underlying issues.

Fixes rdar://108589649.

Author: DougGregor

lib/AST/Decl.cpp

@@ -10752,15 +10752,6 @@ void MacroDecl::getIntroducedNames(MacroRole role, ValueDecl *attachedTo,
     switch (expandedName.getKind()) {
     case MacroIntroducedDeclNameKind::Named: {
       names.push_back(DeclName(expandedName.getName()));
-
-      // Temporary hack: we previously allowed named(`init`) to mean the same
-      // thing as named(init), before the latter was supported. Smooth over the
-      // difference by treating the former as the latter, for a short time.
-      if (expandedName.getName().isSimpleName() &&
-          !expandedName.getName().getBaseName().isSpecial() &&
-          expandedName.getName().getBaseIdentifier().is("init"))
-        names.push_back(DeclName(DeclBaseName::createConstructor()));
-
       break;
     }
 

test/Macros/macro_expand_synthesized_members.swift

@@ -2,7 +2,7 @@
 //
 // RUN: %empty-directory(%t)
 // RUN: %host-build-swift -swift-version 5 -emit-library -o %t/%target-library-name(MacroDefinition) -module-name=MacroDefinition %S/Inputs/syntax_macro_definitions.swift -g -no-toolchain-stdlib-rpath
-// RUN: %target-typecheck-verify-swift -swift-version 5 -load-plugin-library %t/%target-library-name(MacroDefinition) -module-name MacroUser -DTEST_DIAGNOSTICS -swift-version 5
+// RUN: %target-typecheck-verify-swift -swift-version 5 -load-plugin-library %t/%target-library-name(MacroDefinition) -module-name MacroUser -DTEST_DIAGNOSTICS -swift-version 5 -verify-ignore-unknown
 // RUN: %target-build-swift -g -swift-version 5 -load-plugin-library %t/%target-library-name(MacroDefinition) %s -o %t/main -module-name MacroUser -swift-version 5
 // RUN: %target-codesign %t/main
 // RUN: %target-run %t/main | %FileCheck %s
@@ -96,10 +96,12 @@ enum ElementType {
 
 print(ElementType.paper.unknown())
 
+#if TEST_DIAGNOSTICS
 @addMembersQuotedInit
-struct S2 {
+struct S2 { // expected-note{{in expansion of macro 'addMembersQuotedInit' here}}
   func useSynthesized() {
     S.method()
     print(type(of: getStorage()))
   }
 }
+#endif