JS_IR: DCE

Could be enabled by toggling `-Xir-dce`

Box test output in js/js.translator/testData/out-min

libraries/stdlib/js-ir/runtime/coreRuntime.kt

@@ -55,7 +55,7 @@ fun hashCode(obj: dynamic): Int {
     }
 }
 
-private var POW_2_32 = 4294967296
+private var POW_2_32 = 4294967296.0
 private var OBJECT_HASH_CODE_PROPERTY_NAME = "kotlinHashCodeValue$"
 
 fun getObjectHashCode(obj: dynamic): Int {
@@ -83,7 +83,9 @@ fun identityHashCode(obj: Any?): Int = getObjectHashCode(obj)
 
 internal fun captureStack(instance: Throwable) {
     if (js("Error").captureStackTrace != null) {
-        js("Error").captureStackTrace(instance, instance::class.js)
+        // TODO Why we generated get kclass for throwable in original code?
+        js("Error").captureStackTrace(instance, instance.asDynamic().constructor)
+//        js("Error").captureStackTrace(instance, instance::class.js)
     } else {
         instance.asDynamic().stack = js("new Error()").stack
     }

libraries/stdlib/js/src/kotlin/console.kt

@@ -65,7 +65,7 @@ internal open class BufferedOutput : BaseOutput() {
 internal class BufferedOutputToConsoleLog : BufferedOutput() {
     override fun print(message: Any?) {
         var s = String(message)
-        val i = s.lastIndexOf('\n')
+        val i = s.nativeLastIndexOf("\n", 0)
         if (i >= 0) {
             buffer += s.substring(0, i)
             flush()