Finally drop deprecated mod functions from numeric types

#KT-26654

libraries/stdlib/jvm/test/numbers/BigNumbersTest.kt

@@ -1,5 +1,5 @@
 /*
- * Copyright 2010-2018 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Copyright 2010-2020 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.
  */
 
@@ -72,7 +72,6 @@ class BigNumbersTest {
         assertEquals(BigDecimal("2"), BigDecimal("4") / a)
         assertEquals(BigDecimal("-2"), -a)
         assertEquals(BigDecimal("-2"), -a % b)
-        assertEquals(BigDecimal("-2"), @Suppress("DEPRECATION_ERROR") (-a).mod(b))
         assertEquals(BigDecimal("-2"), (-a).rem(b))
 
         assertEquals(BigDecimal("3"), a.inc())