Rename prefix --> showAsPrefix

Author: odersky

compiler/src/dotty/tools/dotc/cc/CaptureSet.scala

@@ -1310,7 +1310,7 @@ object CaptureSet:
       res.myTrace = cs1 :: this.myTrace
       res
 
-    override def prefix(using Context) = cs match
+    override def showAsPrefix(using Context) = cs match
       case cs: Var =>
         !cs.levelOK(elem)
         || cs.isBadRoot(elem) && elem.isInstanceOf[FreshCap]

compiler/src/dotty/tools/dotc/reporting/Message.scala

@@ -47,7 +47,7 @@ object Message:
   	/** Should the note be shown before the actual message or after?
   	 *  Default is after.
   	 */
-    def prefix(using Context): Boolean = false
+    def showAsPrefix(using Context): Boolean = false
 
     /** The note rendered as part of an error message */
     def render(using Context): String

compiler/src/dotty/tools/dotc/reporting/messages.scala

@@ -343,7 +343,7 @@ class TypeMismatch(val found: Type, expected: Type, val inTree: Option[untpd.Tre
           mapOver(tp)
         case _ =>
           mapOver(tp)
-    val preface = notes.filter(_.prefix).map(_.render).mkString
+    val preface = notes.filter(_.showAsPrefix).map(_.render).mkString
     val found1 = reported(found)
     reported.setVariance(-1)
     val expected1 = reported(expected)
@@ -359,7 +359,7 @@ class TypeMismatch(val found: Type, expected: Type, val inTree: Option[untpd.Tre
     def importSuggestions =
       if expected.isTopType || found.isBottomType then ""
       else ctx.typer.importSuggestionAddendum(ViewProto(found.widen, expected))
-    notes.filter(!_.prefix).map(_.render).mkString ++ super.msgPostscript ++ importSuggestions
+    notes.filter(!_.showAsPrefix).map(_.render).mkString ++ super.msgPostscript ++ importSuggestions
 
   override def explain(using Context) =
     val treeStr = inTree.map(x => s"\nTree:\n\n${x.show}\n").getOrElse("")