[JS BE] Support val in when subject

#KT-25014 Fixed

compiler/testData/codegen/box/when/whenSubjectVariable/captureSubjectVariable.kt

@@ -1,5 +1,4 @@
 // !LANGUAGE: +VariableDeclarationInWhenSubject
-// IGNORE_BACKEND: JS
 
 fun box(): String {
     var y: String = "OK"

compiler/testData/codegen/box/when/whenSubjectVariable/denseIntSwitchWithSubjectVariable.kt

@@ -1,6 +1,6 @@
 // !LANGUAGE: +VariableDeclarationInWhenSubject
 // WITH_RUNTIME
-// IGNORE_BACKEND: JS, JS_IR
+// IGNORE_BACKEND: JS_IR
 
 fun dense(x: Int): Int {
     return when (val xx = x) {

compiler/testData/codegen/box/when/whenSubjectVariable/equalityWithSubjectVariable.kt

@@ -1,5 +1,4 @@
 // !LANGUAGE: +VariableDeclarationInWhenSubject
-// IGNORE_BACKEND: JS
 
 val x = 1
 

compiler/testData/codegen/box/when/whenSubjectVariable/ieee754Equality.kt

@@ -1,5 +1,4 @@
 // !LANGUAGE: +VariableDeclarationInWhenSubject
-// IGNORE_BACKEND: JS
 
 val dz = -0.0
 val fz = -0.0f
@@ -29,5 +28,14 @@ fun box(): String {
         }
     }
 
+    testDoubleAsUpperBound(-0.0)
+
     return "OK"
-}
+}
+
+fun <T: Double> testDoubleAsUpperBound(v: T): Boolean {
+    return when (val a = v*v) {
+        0.0 -> true
+        else -> throw AssertionError()
+    }
+}

compiler/testData/codegen/box/when/whenSubjectVariable/ieee754EqualityWithSmartCast.kt

@@ -1,22 +1,32 @@
 // !LANGUAGE: +VariableDeclarationInWhenSubject +ProperIeee754Comparisons
 // IGNORE_BACKEND: JVM_IR
-// IGNORE_BACKEND: JS, JS_IR
+// IGNORE_BACKEND: JS_IR
 
 val az: Any = -0.0
 val afz: Any = -0.0f
 
 fun box(): String {
-    when (val y = az) {
+    val y = az
+    when (y) {
         !is Double -> throw AssertionError()
         0.0 -> {}
         else -> throw AssertionError()
     }
-
-    when (val y = afz) {
+    val yy = afz
+    when (yy) {
         !is Float -> throw AssertionError()
         0.0 -> {}
         else -> throw AssertionError()
     }
 
+    testDoubleAsUpperBound(-0.0)
+
     return "OK"
-}
+}
+
+fun <T: Double> testDoubleAsUpperBound(v: T): Boolean {
+    return when (val a = v*v) {
+        0.0 -> true
+        else -> throw AssertionError()
+    }
+}

compiler/testData/codegen/box/when/whenSubjectVariable/isCheckOnSubjectVariable.kt

@@ -1,5 +1,4 @@
 // !LANGUAGE: +VariableDeclarationInWhenSubject
-// IGNORE_BACKEND: JS
 
 val x: Any = 1
 

compiler/testData/codegen/box/when/whenSubjectVariable/sparseIntSwitchWithSubjectVariable.kt

@@ -1,6 +1,6 @@
 // !LANGUAGE: +VariableDeclarationInWhenSubject
 // WITH_RUNTIME
-// IGNORE_BACKEND: JS, JS_IR
+// IGNORE_BACKEND: JS_IR
 
 fun sparse(x: Int): Int {
     return when (val xx = (x % 4) * 100) {

compiler/testData/codegen/box/when/whenSubjectVariable/subjectExpressionIsEvaluatedOnce.kt

@@ -1,5 +1,4 @@
 // !LANGUAGE: +VariableDeclarationInWhenSubject
-// IGNORE_BACKEND: JS
 
 var effectCount = 0
 

compiler/testData/codegen/box/when/whenSubjectVariable/whenByEnum.kt

@@ -1,6 +1,6 @@
 // !LANGUAGE: +VariableDeclarationInWhenSubject
 // WITH_RUNTIME
-// IGNORE_BACKEND: JS, JS_IR
+// IGNORE_BACKEND: JS_IR
 
 import kotlin.test.assertEquals
 

compiler/testData/codegen/box/when/whenSubjectVariable/whenByNullableEnum.kt

@@ -1,6 +1,6 @@
 // !LANGUAGE: +VariableDeclarationInWhenSubject
 // WITH_RUNTIME
-// IGNORE_BACKEND: JS, JS_IR
+// IGNORE_BACKEND: JS_IR
 
 import kotlin.test.assertEquals
 

compiler/testData/codegen/box/when/whenSubjectVariable/whenByString.kt

@@ -1,6 +1,5 @@
 // !LANGUAGE: +VariableDeclarationInWhenSubject
 // WITH_RUNTIME
-// IGNORE_BACKEND: JS
 
 import kotlin.test.assertEquals