KT-6942: in JS backed for value equalitity patterns in when generate structural equality check (i.e. Any.equals) instead of referential check (===).

(cherry picked from commit 97228e5)

js/js.translator/testData/expression/when/cases/whenEqualsPattern.kt

@@ -0,0 +1,87 @@
+package foo
+
+data class A(val bar: Int)
+
+@native class B
+
+fun makeB(): B = js("new Object();")
+
+fun intAgainstInt(x: Int) = when (x) {
+    1 -> "a"
+    2 -> "b"
+    else -> "*"
+}
+
+fun intAgainstNullableInt(x: Int?) = when (x) {
+    1 -> "a"
+    2 -> "b"
+    null -> "c"
+    else -> "*"
+}
+
+fun anyAgainstInt(x: Any?) = when (x) {
+    1 -> "a"
+    2 -> "b"
+    else -> "*"
+}
+
+fun longAgainstLong(x: Long) = when (x) {
+    1L -> "a"
+    2L -> "b"
+    else -> "*"
+}
+
+fun anyAgainstLong(x: Any?) = when (x) {
+    1L -> "a"
+    2L -> "b"
+    null -> "c"
+    else -> "*"
+}
+
+fun anyAgainstAny(x: Any) = when (x) {
+    A(1) -> "a"
+    1 -> "b"
+    else -> "*"
+}
+
+fun dynamicAgainstPattern(x: dynamic) = when(x) {
+    1 -> "a"
+    "2" -> "b"
+    else -> "*"
+}
+
+fun box(): String {
+    assertEquals("a", intAgainstInt(1))
+    assertEquals("b", intAgainstInt(2))
+    assertEquals("*", intAgainstInt(23))
+
+    assertEquals("a", intAgainstNullableInt(1))
+    assertEquals("b", intAgainstNullableInt(2))
+    assertEquals("c", intAgainstNullableInt(null))
+    assertEquals("*", intAgainstNullableInt(23))
+
+    assertEquals("a", anyAgainstInt(1))
+    assertEquals("b", anyAgainstInt(2))
+    assertEquals("*", anyAgainstInt(A(23)))
+
+    assertEquals("a", longAgainstLong(1))
+    assertEquals("b", longAgainstLong(2))
+    assertEquals("*", longAgainstLong(23))
+
+    assertEquals("a", anyAgainstLong(1L))
+    assertEquals("b", anyAgainstLong(2L))
+    assertEquals("c", anyAgainstLong(null))
+    assertEquals("*", anyAgainstLong(A(23)))
+
+    assertEquals("a", anyAgainstAny(A(1)))
+    assertEquals("b", anyAgainstAny(1))
+    assertEquals("*", anyAgainstAny(listOf(1)))
+
+    assertEquals("a", dynamicAgainstPattern(1))
+    assertEquals("a", dynamicAgainstPattern(js("1")))
+    assertEquals("b", dynamicAgainstPattern("2"))
+    assertEquals("b", dynamicAgainstPattern(js("'2'")))
+    assertEquals("*", dynamicAgainstPattern(js("{}")))
+
+    return "OK"
+}