[AST] ASTPrinter: Make sure that attributes are printed as attributes and specifiers as keywords

(cherry picked from commit e302d73)

Author: xedin

lib/AST/ASTPrinter.cpp

@@ -3889,7 +3889,7 @@ static void printParameterFlags(ASTPrinter &printer,
 
   if (flags.isSending()) {
     if (!options.SuppressSendingArgsAndResults) {
-      printer.printAttrName("sending ");
+      printer.printKeyword("sending", options, " ");
     } else if (flags.getOwnershipSpecifier() ==
                ParamSpecifier::ImplicitlyCopyableConsuming) {
       // Ok. We are suppressing sending. If our ownership specifier was
@@ -3910,14 +3910,14 @@ static void printParameterFlags(ASTPrinter &printer,
   // `inout` implies `@escaping`
   if (flags.getOwnershipSpecifier() != ParamSpecifier::InOut) {
     if (!options.excludeAttrKind(TypeAttrKind::Escaping) && escaping)
-      printer.printKeyword("@escaping", options, " ");
+      printer.printAttrName("@escaping ");
   }
 
   if (flags.isCompileTimeLiteral())
     printer.printKeyword("_const", options, " ");
 
   if (flags.isConstValue())
-    printer.printKeyword("@const", options, " ");
+    printer.printAttrName("@const ");
 }
 
 void PrintAST::visitVarDecl(VarDecl *decl) {

test/SymbolGraph/Symbols/Mixins/DeclarationFragments/Full/Function.swift

@@ -39,12 +39,12 @@ public func foo<S>(f: @escaping () -> (), ext int: Int = 2, s: S) where S: Seque
 // CHECK-NEXT:          "spelling": ": "
 // CHECK-NEXT:        },
 // CHECK-NEXT:        {
-// CHECK-NEXT:          "kind": "keyword",
-// CHECK-NEXT:          "spelling": "@escaping"
+// CHECK-NEXT:          "kind": "attribute",
+// CHECK-NEXT:          "spelling": "@escaping "
 // CHECK-NEXT:        },
 // CHECK-NEXT:        {
 // CHECK-NEXT:          "kind": "text",
-// CHECK-NEXT:          "spelling": " () -> (), "
+// CHECK-NEXT:          "spelling": "() -> (), "
 // CHECK-NEXT:        },
 // CHECK-NEXT:        {
 // CHECK-NEXT:          "kind": "externalParam",