JS IR: mute codegen box tests automatically

compiler/testData/codegen/box/unaryOp/call.kt

@@ -1,3 +1,4 @@
+// IGNORE_BACKEND: JS_IR
 fun box(): String {
     val a1: Byte = 1.unaryMinus()
     val a2: Short = 1.unaryMinus()

compiler/testData/codegen/box/unaryOp/callNullable.kt

@@ -1,3 +1,4 @@
+// IGNORE_BACKEND: JS_IR
 fun box(): String {
     val a1: Byte? = 1.unaryMinus()
     val a2: Short? = 1.unaryMinus()

compiler/testData/codegen/box/unaryOp/callWithCommonType.kt

@@ -1,3 +1,4 @@
+// IGNORE_BACKEND: JS_IR
 fun box(): String {
     if (!foo(1.toByte())) return "fail 1"
     if (!foo((1.toByte()).inc())) return "fail 2"

compiler/testData/codegen/box/unaryOp/intrinsic.kt

@@ -1,3 +1,4 @@
+// IGNORE_BACKEND: JS_IR
 fun box(): String {
     val a1: Byte = -1
     val a2: Short = -1

compiler/testData/codegen/box/unaryOp/intrinsicNullable.kt

@@ -1,3 +1,4 @@
+// IGNORE_BACKEND: JS_IR
 fun box(): String {
     val a1: Byte? = -1
     val a2: Short? = -1

compiler/testData/codegen/box/unaryOp/longOverflow.kt

@@ -1,3 +1,4 @@
+// IGNORE_BACKEND: JS_IR
 fun box(): String {
     val a: Long = -(1 shl 31)
     if (a != -2147483648L) return "fail: in this case we should add to ints and than cast the result to long - overflow expected"