Revert "[Macros] Enable composition of member attribute macros and accessor macros."

It causes crashes in some Sema/SwiftUI tests in some configurations.

rdar://104297642

This reverts commit b8d65e1ed9.

lib/AST/Module.cpp

@@ -887,15 +887,6 @@ ASTNode SourceFile::getMacroExpansion() const {
   return ASTNode::getFromOpaqueValue(genInfo.astNode);
 }
 
-CustomAttr *SourceFile::getAttachedMacroAttribute() const {
-  if (Kind != SourceFileKind::MacroExpansion)
-    return nullptr;
-
-  auto genInfo =
-      *getASTContext().SourceMgr.getGeneratedSourceInfo(*getBufferID());
-  return genInfo.attachedMacroCustomAttr;
-}
-
 SourceFile *SourceFile::getEnclosingSourceFile() const {
   auto macroExpansion = getMacroExpansion();
   if (!macroExpansion)