Address review

Author: liufengyun

compiler/src/dotty/tools/dotc/core/classfile/ClassfileParser.scala

@@ -50,11 +50,6 @@ object ClassfileParser {
         mapOver(tp)
     }
   }
-
-  def withReader[T](classfile: AbstractFile)(op: DataReader ?=> T)(using Context): T =
-    ctx.base.reusableDataReader.using { reader =>
-      op(using reader.reset(classfile))
-    }
 }
 
 class ClassfileParser(
@@ -86,11 +81,14 @@ class ClassfileParser(
   private def mismatchError(className: SimpleName) =
     throw new IOException(s"class file '${classfile.canonicalPath}' has location not matching its contents: contains class $className")
 
-  def run()(using Context): Option[Embedded] = try withReader(classfile) { (using in) =>
+  def run()(using Context): Option[Embedded] = try ctx.base.reusableDataReader.using { reader =>
+    implicit val reader2 = reader.reset(classfile)
     report.debuglog("[class] >> " + classRoot.fullName)
     parseHeader()
     this.pool = new ConstantPool
-    parseClass()
+    val res = parseClass()
+    this.pool =  null
+    res
   }
   catch {
     case e: RuntimeException =>