[JS IR BE] Refactor equals and compareTo lowering

compiler/testData/codegen/box/ieee754/dataClass.kt

@@ -1,5 +1,4 @@
 // IGNORE_BACKEND: JVM_IR
-// IGNORE_BACKEND: JS_IR
 data class Test(val z1: Double, val z2: Double?)
 
 fun box(): String {

compiler/testData/codegen/box/ieee754/equalsNaN_properIeeeComparisons.kt

@@ -1,5 +1,6 @@
 // !LANGUAGE: +ProperIeee754Comparisons
 // IGNORE_BACKEND: JVM_IR
+// IGNORE_BACKEND: JS_IR
 // WITH_RUNTIME
 
 import kotlin.test.*
@@ -94,6 +95,7 @@ fun box(): String {
     assertTrue(adnq == dn, "Double: (Any?)NaN != NaN")
     assertTrue(adnq == adn, "Double: (Any?)NaN != (Any)NaN")
 
+    // JS IR fails due to: https://bugs.openjdk.java.net/browse/JDK-8141407
     assertFalse(dnq == dnq, "Double: NaN? == NaN?")
     assertTrue(dnq == adnq, "Double: NaN? != (Any?)NaN")
     assertTrue(adnq == dnq, "Double: (Any?)NaN != NaN?")
@@ -114,6 +116,7 @@ fun box(): String {
     assertFalse(adnq != dn, "Double: (Any?)NaN != NaN")
     assertFalse(adnq != adn, "Double: (Any?)NaN != (Any)NaN")
 
+    // JS IR fails due to: https://bugs.openjdk.java.net/browse/JDK-8141407
     assertTrue(dnq != dnq, "Double: NaN? == NaN?")
     assertFalse(dnq != adnq, "Double: NaN? != (Any?)NaN")
     assertFalse(adnq != dnq, "Double: (Any?)NaN != NaN?")

compiler/testData/codegen/box/ieee754/inline.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JS_IR
 inline fun less(a: Comparable<Double>, b: Double): Boolean {
     return a < b
 }