Do not box primitives for 'primitive == object'

NB user-defined 'equals' can violate contract for 'Object#equals', e.g.,
it can be asymmetric.
Thus we can't avoid boxing for 'object == primitive'.

compiler/testData/codegen/box/primitiveTypes/equalityWithObject/boxedLongEqualsLong.kt

@@ -0,0 +1,6 @@
+val x: Long = 0L
+
+fun box(): String {
+    val ax: Long? = 0L
+    return if (ax != x) "Fail" else "OK"
+}

compiler/testData/codegen/box/primitiveTypes/equalityWithObject/generated/primitiveEqObjectBoolean.kt

@@ -0,0 +1,47 @@
+// Auto-generated by GeneratePrimitiveVsObjectEqualityTestData. Do not edit!
+
+val nx: Any? = true
+val nn: Any? = null
+val x: Boolean = true
+val y: Boolean = false
+
+fun box(): String {
+    val ax: Any? = true
+    val an: Any? = null
+    val bx: Boolean = true
+    val by: Boolean = false
+
+    return when {
+        true != nx -> "Fail 0"
+        false == nx -> "Fail 1"
+        !(true == nx) -> "Fail 2"
+        !(false != nx) -> "Fail 3"
+        x != nx -> "Fail 4"
+        y == nx -> "Fail 5"
+        !(x == nx) -> "Fail 6"
+        !(y != nx) -> "Fail 7"
+        true == nn -> "Fail 8"
+        !(true != nn) -> "Fail 9"
+        x == nn -> "Fail 10"
+        !(x != nn) -> "Fail 11"
+        true != ax -> "Fail 12"
+        false == ax -> "Fail 13"
+        !(true == ax) -> "Fail 14"
+        !(false != ax) -> "Fail 15"
+        x != ax -> "Fail 16"
+        y == ax -> "Fail 17"
+        !(x == ax) -> "Fail 18"
+        !(y != ax) -> "Fail 19"
+        bx != ax -> "Fail 20"
+        by == ax -> "Fail 21"
+        !(bx == ax) -> "Fail 22"
+        !(by != ax) -> "Fail 23"
+        true == an -> "Fail 24"
+        !(true != an) -> "Fail 25"
+        x == an -> "Fail 26"
+        !(x != an) -> "Fail 27"
+        bx == an -> "Fail 28"
+        !(bx != an) -> "Fail 29"
+        else -> "OK"
+    }
+}

compiler/testData/codegen/box/primitiveTypes/equalityWithObject/generated/primitiveEqObjectByte.kt

@@ -0,0 +1,47 @@
+// Auto-generated by GeneratePrimitiveVsObjectEqualityTestData. Do not edit!
+
+val nx: Any? = 0.toByte()
+val nn: Any? = null
+val x: Byte = 0.toByte()
+val y: Byte = 1.toByte()
+
+fun box(): String {
+    val ax: Any? = 0.toByte()
+    val an: Any? = null
+    val bx: Byte = 0.toByte()
+    val by: Byte = 1.toByte()
+
+    return when {
+        0.toByte() != nx -> "Fail 0"
+        1.toByte() == nx -> "Fail 1"
+        !(0.toByte() == nx) -> "Fail 2"
+        !(1.toByte() != nx) -> "Fail 3"
+        x != nx -> "Fail 4"
+        y == nx -> "Fail 5"
+        !(x == nx) -> "Fail 6"
+        !(y != nx) -> "Fail 7"
+        0.toByte() == nn -> "Fail 8"
+        !(0.toByte() != nn) -> "Fail 9"
+        x == nn -> "Fail 10"
+        !(x != nn) -> "Fail 11"
+        0.toByte() != ax -> "Fail 12"
+        1.toByte() == ax -> "Fail 13"
+        !(0.toByte() == ax) -> "Fail 14"
+        !(1.toByte() != ax) -> "Fail 15"
+        x != ax -> "Fail 16"
+        y == ax -> "Fail 17"
+        !(x == ax) -> "Fail 18"
+        !(y != ax) -> "Fail 19"
+        bx != ax -> "Fail 20"
+        by == ax -> "Fail 21"
+        !(bx == ax) -> "Fail 22"
+        !(by != ax) -> "Fail 23"
+        0.toByte() == an -> "Fail 24"
+        !(0.toByte() != an) -> "Fail 25"
+        x == an -> "Fail 26"
+        !(x != an) -> "Fail 27"
+        bx == an -> "Fail 28"
+        !(bx != an) -> "Fail 29"
+        else -> "OK"
+    }
+}

compiler/testData/codegen/box/primitiveTypes/equalityWithObject/generated/primitiveEqObjectChar.kt

@@ -0,0 +1,47 @@
+// Auto-generated by GeneratePrimitiveVsObjectEqualityTestData. Do not edit!
+
+val nx: Any? = '0'
+val nn: Any? = null
+val x: Char = '0'
+val y: Char = '1'
+
+fun box(): String {
+    val ax: Any? = '0'
+    val an: Any? = null
+    val bx: Char = '0'
+    val by: Char = '1'
+
+    return when {
+        '0' != nx -> "Fail 0"
+        '1' == nx -> "Fail 1"
+        !('0' == nx) -> "Fail 2"
+        !('1' != nx) -> "Fail 3"
+        x != nx -> "Fail 4"
+        y == nx -> "Fail 5"
+        !(x == nx) -> "Fail 6"
+        !(y != nx) -> "Fail 7"
+        '0' == nn -> "Fail 8"
+        !('0' != nn) -> "Fail 9"
+        x == nn -> "Fail 10"
+        !(x != nn) -> "Fail 11"
+        '0' != ax -> "Fail 12"
+        '1' == ax -> "Fail 13"
+        !('0' == ax) -> "Fail 14"
+        !('1' != ax) -> "Fail 15"
+        x != ax -> "Fail 16"
+        y == ax -> "Fail 17"
+        !(x == ax) -> "Fail 18"
+        !(y != ax) -> "Fail 19"
+        bx != ax -> "Fail 20"
+        by == ax -> "Fail 21"
+        !(bx == ax) -> "Fail 22"
+        !(by != ax) -> "Fail 23"
+        '0' == an -> "Fail 24"
+        !('0' != an) -> "Fail 25"
+        x == an -> "Fail 26"
+        !(x != an) -> "Fail 27"
+        bx == an -> "Fail 28"
+        !(bx != an) -> "Fail 29"
+        else -> "OK"
+    }
+}

compiler/testData/codegen/box/primitiveTypes/equalityWithObject/generated/primitiveEqObjectInt.kt

@@ -0,0 +1,47 @@
+// Auto-generated by GeneratePrimitiveVsObjectEqualityTestData. Do not edit!
+
+val nx: Any? = 0
+val nn: Any? = null
+val x: Int = 0
+val y: Int = 1
+
+fun box(): String {
+    val ax: Any? = 0
+    val an: Any? = null
+    val bx: Int = 0
+    val by: Int = 1
+
+    return when {
+        0 != nx -> "Fail 0"
+        1 == nx -> "Fail 1"
+        !(0 == nx) -> "Fail 2"
+        !(1 != nx) -> "Fail 3"
+        x != nx -> "Fail 4"
+        y == nx -> "Fail 5"
+        !(x == nx) -> "Fail 6"
+        !(y != nx) -> "Fail 7"
+        0 == nn -> "Fail 8"
+        !(0 != nn) -> "Fail 9"
+        x == nn -> "Fail 10"
+        !(x != nn) -> "Fail 11"
+        0 != ax -> "Fail 12"
+        1 == ax -> "Fail 13"
+        !(0 == ax) -> "Fail 14"
+        !(1 != ax) -> "Fail 15"
+        x != ax -> "Fail 16"
+        y == ax -> "Fail 17"
+        !(x == ax) -> "Fail 18"
+        !(y != ax) -> "Fail 19"
+        bx != ax -> "Fail 20"
+        by == ax -> "Fail 21"
+        !(bx == ax) -> "Fail 22"
+        !(by != ax) -> "Fail 23"
+        0 == an -> "Fail 24"
+        !(0 != an) -> "Fail 25"
+        x == an -> "Fail 26"
+        !(x != an) -> "Fail 27"
+        bx == an -> "Fail 28"
+        !(bx != an) -> "Fail 29"
+        else -> "OK"
+    }
+}

compiler/testData/codegen/box/primitiveTypes/equalityWithObject/generated/primitiveEqObjectLong.kt

@@ -0,0 +1,47 @@
+// Auto-generated by GeneratePrimitiveVsObjectEqualityTestData. Do not edit!
+
+val nx: Any? = 0L
+val nn: Any? = null
+val x: Long = 0L
+val y: Long = 1L
+
+fun box(): String {
+    val ax: Any? = 0L
+    val an: Any? = null
+    val bx: Long = 0L
+    val by: Long = 1L
+
+    return when {
+        0L != nx -> "Fail 0"
+        1L == nx -> "Fail 1"
+        !(0L == nx) -> "Fail 2"
+        !(1L != nx) -> "Fail 3"
+        x != nx -> "Fail 4"
+        y == nx -> "Fail 5"
+        !(x == nx) -> "Fail 6"
+        !(y != nx) -> "Fail 7"
+        0L == nn -> "Fail 8"
+        !(0L != nn) -> "Fail 9"
+        x == nn -> "Fail 10"
+        !(x != nn) -> "Fail 11"
+        0L != ax -> "Fail 12"
+        1L == ax -> "Fail 13"
+        !(0L == ax) -> "Fail 14"
+        !(1L != ax) -> "Fail 15"
+        x != ax -> "Fail 16"
+        y == ax -> "Fail 17"
+        !(x == ax) -> "Fail 18"
+        !(y != ax) -> "Fail 19"
+        bx != ax -> "Fail 20"
+        by == ax -> "Fail 21"
+        !(bx == ax) -> "Fail 22"
+        !(by != ax) -> "Fail 23"
+        0L == an -> "Fail 24"
+        !(0L != an) -> "Fail 25"
+        x == an -> "Fail 26"
+        !(x != an) -> "Fail 27"
+        bx == an -> "Fail 28"
+        !(bx != an) -> "Fail 29"
+        else -> "OK"
+    }
+}

compiler/testData/codegen/box/primitiveTypes/equalityWithObject/generated/primitiveEqObjectShort.kt

@@ -0,0 +1,47 @@
+// Auto-generated by GeneratePrimitiveVsObjectEqualityTestData. Do not edit!
+
+val nx: Any? = 0.toShort()
+val nn: Any? = null
+val x: Short = 0.toShort()
+val y: Short = 1.toShort()
+
+fun box(): String {
+    val ax: Any? = 0.toShort()
+    val an: Any? = null
+    val bx: Short = 0.toShort()
+    val by: Short = 1.toShort()
+
+    return when {
+        0.toShort() != nx -> "Fail 0"
+        1.toShort() == nx -> "Fail 1"
+        !(0.toShort() == nx) -> "Fail 2"
+        !(1.toShort() != nx) -> "Fail 3"
+        x != nx -> "Fail 4"
+        y == nx -> "Fail 5"
+        !(x == nx) -> "Fail 6"
+        !(y != nx) -> "Fail 7"
+        0.toShort() == nn -> "Fail 8"
+        !(0.toShort() != nn) -> "Fail 9"
+        x == nn -> "Fail 10"
+        !(x != nn) -> "Fail 11"
+        0.toShort() != ax -> "Fail 12"
+        1.toShort() == ax -> "Fail 13"
+        !(0.toShort() == ax) -> "Fail 14"
+        !(1.toShort() != ax) -> "Fail 15"
+        x != ax -> "Fail 16"
+        y == ax -> "Fail 17"
+        !(x == ax) -> "Fail 18"
+        !(y != ax) -> "Fail 19"
+        bx != ax -> "Fail 20"
+        by == ax -> "Fail 21"
+        !(bx == ax) -> "Fail 22"
+        !(by != ax) -> "Fail 23"
+        0.toShort() == an -> "Fail 24"
+        !(0.toShort() != an) -> "Fail 25"
+        x == an -> "Fail 26"
+        !(x != an) -> "Fail 27"
+        bx == an -> "Fail 28"
+        !(bx != an) -> "Fail 29"
+        else -> "OK"
+    }
+}

compiler/testData/codegen/box/primitiveTypes/equalityWithObject/objectWithAsymmetricEqualsEqPrimitive.kt

@@ -0,0 +1,20 @@
+// Strictly speaking, asymmetric equals violates contract for 'Object#equals'.
+// However, we don't rely on this contract so far.
+class FakeInt(val value: Int) {
+    override fun equals(other: Any?): Boolean =
+            other is Int && other == value
+}
+
+fun box(): String {
+    val fake: Any = FakeInt(42)
+
+    val int1 = 1
+    val int42 = 42
+
+    if (fake == int1) return "FakeInt(42) == 1"
+    if (fake != int42) return "FakeInt(42) != 42"
+    if (int1 == fake) return "1 == FakeInt(42)"
+    if (int42 == fake) return "42 == FakeInt(42)"
+
+    return "OK"
+}