Floor division and remainder for numeric types KT-26234

- floorDiv/mod for unsigned types
- floorDiv/mod for signed types
- mod for floating point types

- mod return type: same as divisor for integer types

- Update JS API dump
- Avoid triggering division overflow in tests due to K/N
- Workaround failing test in JS-legacy

libraries/stdlib/test/unsigned/UIntTest.kt

@@ -1,15 +1,12 @@
 /*
- * Copyright 2010-2018 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Copyright 2010-2021 JetBrains s.r.o. and Kotlin Programming Language contributors.
  * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
  */
 
 package test.unsigned
 
-import kotlin.math.nextDown
-import kotlin.math.nextUp
-import kotlin.math.pow
-import kotlin.math.sign
-import kotlin.random.Random
+import kotlin.math.*
+import kotlin.random.*
 import kotlin.test.*
 
 class UIntTest {
@@ -69,6 +66,42 @@ class UIntTest {
         testToString("4294967295", UInt.MAX_VALUE)
     }
 
+    @Test
+    fun operations() {
+        assertEquals(2_147_483_648u, Int.MAX_VALUE.toUInt() + identity(1u))
+        assertEquals(11u, UInt.MAX_VALUE + identity(12u))
+        assertEquals(UInt.MAX_VALUE - 99u, 45u - identity(145u))
+
+        assertEquals(UInt.MAX_VALUE - 1u, Int.MAX_VALUE.toUInt() * identity(2u))
+        assertEquals(2_147_483_645u, Int.MAX_VALUE.toUInt() * identity(3u))
+
+        testMulDivRem(125u, 3u, 41u, 2u)
+        testMulDivRem(210u, 5u, 42u, 0u)
+        testMulDivRem(UInt.MAX_VALUE, 256u, 16777215u, 255u)
+        testMulDivRem(UInt.MAX_VALUE - 1u, UInt.MAX_VALUE, 0u, UInt.MAX_VALUE - 1u)
+        testMulDivRem(UInt.MAX_VALUE, UInt.MAX_VALUE - 1u, 1u, 1u)
+        testMulDivRem(UInt.MAX_VALUE, Int.MAX_VALUE.toUInt(), 2u, 1u)
+    }
+
+
+    private fun testMulDivRem(number: UInt, divisor: UInt, div: UInt, rem: UInt) {
+        assertEquals(div, number / divisor)
+        assertEquals(rem, number % divisor)
+        assertEquals(div, number.floorDiv(divisor))
+        assertEquals(rem, number.mod(divisor))
+
+        assertEquals(number, div * divisor + rem)
+        assertTrue(rem < divisor)
+        assertTrue(div < number)
+    }
+
+    @Test
+    fun divRem() = repeat(1000) {
+        val number = Random.nextUInt()
+        val divisor = Random.nextUInt(until = UInt.MAX_VALUE) + 1u
+        testMulDivRem(number, divisor, number / divisor, number % divisor)
+    }
+
     @Test
     fun comparisons() {
         fun <T> compare(op1: Comparable<T>, op2: T) = op1.compareTo(op2)