[parse] Generalize "Need experimental feature flag" parser error to work for general experimental features instead of just NonEscapableTypes.

Author: gottesmm

include/swift/AST/DiagnosticsParse.def

@@ -2160,10 +2160,10 @@ ERROR(duplicate_storage_restrictions_attr_label,none,
 ERROR(storage_restrictions_attr_expected_name,none,
       "expected property name in @storageRestrictions list", ())
 
-ERROR(requires_non_escapable_types, none,
-      "'%0' %select{attribute|parameter specifier}1 is only valid when experimental "
-      "NonescapableTypes is enabled",
-      (StringRef, bool))
+ERROR(requires_experimental_feature, none,
+      "'%0' %select{attribute|parameter specifier}1 is only valid when experimental feature "
+      "%2 is enabled",
+      (StringRef, bool, StringRef))
 
 #define UNDEFINE_DIAGNOSTIC_MACROS
 #include "DefineDiagnosticMacros.h"

lib/Parse/ParseDecl.cpp

@@ -2873,7 +2873,8 @@ ParserStatus Parser::parseNewDeclAttribute(DeclAttributes &Attributes,
 
   if (DK == DAK_ResultDependsOnSelf &&
       !Context.LangOpts.hasFeature(Feature::NonescapableTypes)) {
-    diagnose(Loc, diag::requires_non_escapable_types, AttrName, true);
+    diagnose(Loc, diag::requires_experimental_feature, AttrName, true,
+             getFeatureName(Feature::NonescapableTypes));
     DiscardAttribute = true;
   }
 
@@ -5161,8 +5162,8 @@ ParserStatus Parser::parseTypeAttributeListPresent(
 
     if (Tok.isContextualKeyword("_resultDependsOn")) {
       if (!Context.LangOpts.hasFeature(Feature::NonescapableTypes)) {
-        diagnose(Tok, diag::requires_non_escapable_types, "resultDependsOn",
-                 false);
+        diagnose(Tok, diag::requires_experimental_feature, "resultDependsOn",
+                 false, getFeatureName(Feature::NonescapableTypes));
       }
       ResultDependsOnLoc = consumeToken();
       continue;