Remove redundant extraction

Author: nicolasstucki

compiler/src/dotty/tools/backend/jvm/BCodeBodyBuilder.scala

@@ -782,11 +782,8 @@ trait BCodeBodyBuilder extends BCodeSkelBuilder {
             if (invokeStyle.hasInstance) genLoadQualifier(fun)
             genLoadArguments(args, paramTKs(app))
 
-            val DesugaredSelect(qual, _) = fun // fun is a Select, also checked in genLoadQualifier
-            val isArrayClone = fun match {
-              case DesugaredSelect(qual, nme.clone_) if qual.tpe.widen.isInstanceOf[JavaArrayType] => true
-              case _ => false
-            }
+            val DesugaredSelect(qual, name) = fun // fun is a Select, also checked in genLoadQualifier
+            val isArrayClone = name == nme.clone_ && qual.tpe.widen.isInstanceOf[JavaArrayType]
             if (isArrayClone) {
               // Special-case Array.clone, introduced in 36ef60e. The goal is to generate this call
               // as "[I.clone" instead of "java/lang/Object.clone". This is consistent with javac.