AST: Remove the unused SuppressNoAsyncAvailabilityAttr print option.

Author: tshortli

include/swift/AST/PrintOptions.h

@@ -341,9 +341,6 @@ struct PrintOptions {
   /// Whether to print the internal layout name instead of AnyObject, etc.
   bool PrintInternalLayoutName = false;
 
-  /// Suppress emitting @available(*, noasync)
-  bool SuppressNoAsyncAvailabilityAttr = false;
-
   /// Suppress emitting isolated or async deinit, and emit open containing class
   /// as public
   bool SuppressIsolatedDeinit = false;

lib/AST/Attr.cpp

@@ -1159,8 +1159,6 @@ bool DeclAttribute::printImpl(ASTPrinter &Printer, const PrintOptions &Options,
 
   case DeclAttrKind::Available: {
     auto Attr = cast<AvailableAttr>(this);
-    if (Options.SuppressNoAsyncAvailabilityAttr && Attr->isNoAsync())
-      return false;
     if (Options.printPublicInterface() && Attr->isSPI()) {
       assert(Attr->hasPlatform());
       assert(Attr->Introduced.has_value());