JS_IR: DCE

Could be enabled by toggling `-Xir-dce`

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

js/js.translator/testData/box/coercion/charValParameter.kt

@@ -1,5 +1,7 @@
 // EXPECTED_REACHABLE_NODES: 1276
 // IGNORE_BACKEND: JS_IR
+
+@JsExport
 class A(val x: Char)
 
 fun typeOf(x: dynamic): String = js("typeof x")

js/js.translator/testData/box/coercion/defaultAccessors.kt

@@ -4,6 +4,7 @@ interface I {
     val a: Char
 }
 
+@JsExport
 object X : I {
     override var a = '#'
 }

js/js.translator/testData/box/coercion/propertyBridgeChar.kt

@@ -1,5 +1,7 @@
 // EXPECTED_REACHABLE_NODES: 1289
 // IGNORE_BACKEND: JS_IR
+
+@JsExport
 open class A {
     val foo: Char
         get() = 'X'

js/js.translator/testData/box/delegation/jsNamePropertyDelegation.kt

@@ -3,6 +3,7 @@ package foo
 
 import kotlin.reflect.KProperty
 
+@JsExport
 class A {
     @JsName("xx") val x: Int by B(23)
 

js/js.translator/testData/box/jsName/avoidNameClash.kt

@@ -1,5 +1,6 @@
 // EXPECTED_REACHABLE_NODES: 1290
 
+@JsExport
 object A {
     @JsName("js_method") fun f() = "method"
 

js/js.translator/testData/box/jsName/simpleJsName.kt

@@ -1,5 +1,6 @@
 // EXPECTED_REACHABLE_NODES: 1291
 
+@JsExport
 object A {
     @JsName("js_f") fun f(x: Int) = "f($x)"
 

js/js.translator/testData/box/native/undefined.kt

@@ -13,7 +13,7 @@ fun box(): String {
     assertEquals(a.foo, undefined)
     assertNotEquals(a.toString, undefined)
 
-    val b: dynamic = object {val bar = ""}
+    val b: dynamic = object {@JsName("bar") val bar = ""}
     assertEquals(b.foo, undefined)
     assertNotEquals(b.bar, undefined)
 

js/js.translator/testData/box/propertyAccess/simpleLateInitIsInitialized.kt

@@ -7,6 +7,7 @@ fun deinitialize(foo: dynamic) {
 }
 
 class Foo {
+    @JsName("bar")
     lateinit var bar: String
 
     fun test(): String {