Macros are not experimental

Author: liufengyun

compiler/src/dotty/tools/dotc/config/Feature.scala

@@ -26,6 +26,7 @@ object Feature:
   val dependent = experimental("dependent")
   val erasedDefinitions = experimental("erasedDefinitions")
   val symbolLiterals: TermName = deprecated("symbolLiterals")
+  val macros = experimental("macros")
 
   val experimentalWarningMessage = "Experimental features may only be used with nightly or snapshot version of compiler."
 
@@ -36,8 +37,8 @@ object Feature:
 
   def isExperimental(feature: TermName): Boolean =
     feature match
-    case QualifiedName(nme.experimental, _) => true
-    case _ => true
+    case QualifiedName(nme.experimental, _) => feature != macros
+    case _ => false
 
   /** Is `feature` enabled by by a command-line setting? The enabling setting is
    *