Use HALF_EVEN rounding mode by default for BigDecimal division operator.

#KT-10462 Fixed

libraries/stdlib/src/kotlin/util/BigNumbers.kt

@@ -5,6 +5,7 @@ package kotlin
 
 import java.math.BigDecimal
 import java.math.BigInteger
+import java.math.RoundingMode
 
 /**
  * Enables the use of the `+` operator for [BigInteger] instances.
@@ -57,9 +58,12 @@ public inline operator fun BigDecimal.times(other: BigDecimal) : BigDecimal = th
 
 /**
  * Enables the use of the `/` operator for [BigDecimal] instances.
+ *
+ * The scale of the result is the same as the scale of `this` (divident), and for rounding the [RoundingMode.HALF_EVEN]
+ * rounding mode is used.
  */
 @kotlin.internal.InlineOnly
-public inline operator fun BigDecimal.div(other: BigDecimal) : BigDecimal = this.divide(other)
+public inline operator fun BigDecimal.div(other: BigDecimal) : BigDecimal = this.divide(other, RoundingMode.HALF_EVEN)
 
 /**
  * Enables the use of the `%` operator for [BigDecimal] instances.

libraries/stdlib/test/numbers/NumbersJVMTest.kt

@@ -1,5 +1,6 @@
 package numbers
 
+import java.math.BigDecimal
 import org.junit.Test as test
 import kotlin.test.*
 
@@ -38,4 +39,15 @@ class NumbersJVMTest {
         assertEquals(java.lang.Float.POSITIVE_INFINITY, Float.POSITIVE_INFINITY)
         assertEquals(java.lang.Float.NEGATIVE_INFINITY, Float.NEGATIVE_INFINITY)
     }
+
+    @test fun bigDecimalDivRounding() {
+        val (d1, d2, d3, d4, d5) = (1..5).map { BigDecimal(it.toString()) }
+        val d7 = BigDecimal("7")
+
+        assertEquals(d1, d2 / d3)
+        assertEquals(d2, d3 / d2)
+        assertEquals(d2, d5 / d2)
+        assertEquals(d4, d7 / d2)
+        assertEquals(d1, d7 / d5)
+    }
 }