math/big, math/rand: use the built-in max function

src/math/big/nat.go

@@ -389,13 +389,6 @@ func addAt(z, x nat, i int) {
 	}
 }
 
-func max(x, y int) int {
-	if x > y {
-		return x
-	}
-	return y
-}
-
 // karatsubaLen computes an approximation to the maximum k <= n such that
 // k = p<<i for a number p <= threshold and an i >= 0. Thus, the
 // result is the largest number that can be divided repeatedly by 2 before

src/math/rand/rand_test.go

@@ -33,13 +33,6 @@ type statsResults struct {
 	maxError    float64
 }
 
-func max(a, b float64) float64 {
-	if a > b {
-		return a
-	}
-	return b
-}
-
 func nearEqual(a, b, closeEnough, maxError float64) bool {
 	absDiff := math.Abs(a - b)
 	if absDiff < closeEnough { // Necessary when one value is zero and one value is close to zero.