math/big: disable TestNewIntAllocs on noopt builder

Since when that test requires inlining, which is disabled on noopt
builder.

Updates #29951

Change-Id: I9d7a0a64015a30d3bfb5ad5d806ea0955657fda3
Reviewed-on: https://go-review.googlesource.com/c/go/+/422039
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Auto-Submit: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Reviewed-by: Than McIntosh <thanm@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>

src/math/big/int_test.go

@@ -8,6 +8,7 @@ import (
 	"bytes"
 	"encoding/hex"
 	"fmt"
+	"internal/testenv"
 	"math"
 	"math/rand"
 	"strconv"
@@ -1905,6 +1906,9 @@ func TestNewIntMinInt64(t *testing.T) {
 }
 
 func TestNewIntAllocs(t *testing.T) {
+	if strings.HasSuffix(testenv.Builder(), "-noopt") {
+		t.Skip("inlining is disabled on noopt builder")
+	}
 	for _, n := range []int64{0, 7, -7, 1 << 30, -1 << 30, 1 << 50, -1 << 50} {
 		x := NewInt(3)
 		got := testing.AllocsPerRun(100, func() {