[JS IR] Emit original names for local vars to sourcemaps

#KT-35655 Fixed

compiler/testData/debug/localVariables/suspend/simple.kt

@@ -5,6 +5,10 @@ suspend fun box() {
     var x = 1
 }
 
-// EXPECTATIONS
+// EXPECTATIONS JVM JVM_IR
 // test.kt:5 box: $completion:kotlin.coroutines.Continuation=Generated_Box_MainKt$main$1
 // test.kt:6 box: $completion:kotlin.coroutines.Continuation=Generated_Box_MainKt$main$1, x:int=1:int
+
+// EXPECTATIONS JS_IR
+// test.kt:5 box: $completion=EmptyContinuation
+// test.kt:6 box: $completion=EmptyContinuation, x=1:number