JVM IR: do not generate JvmName on multifile parts

#KT-36970 Fixed

compiler/testData/codegen/bytecodeListing/defaultArguments/privateFunctionInMultifilePart.kt

@@ -1,5 +1,5 @@
 // WITH_RUNTIME
-// The remaining differences of JVM and JVM_IR here are reported at KT-36970, KT-41841.
+// The remaining difference of JVM and JVM_IR here is reported at KT-41841.
 
 @file:JvmMultifileClass
 @file:JvmName("A")

compiler/testData/codegen/bytecodeListing/defaultArguments/privateFunctionInMultifilePart_ir.txt

@@ -5,7 +5,6 @@ public final class A {
 }
 
 @kotlin.Metadata
-@kotlin.jvm.JvmName
 synthetic final class A__PrivateFunctionInMultifilePartKt {
     // source: 'privateFunctionInMultifilePart.kt'
     synthetic static method foo$A__PrivateFunctionInMultifilePartKt$default(p0: java.lang.String, p1: int, p2: java.lang.Object): void