message: state-surgery: fix flakey tests
  Sometimes `require.Equal` flakes on the comparison
  of `big.Int`.
diff: @@ -28,7 +28,7 @@ func TestAddBalance(t *testing.T) {
  account := db.GetAccount(addr)
  require.NotNil(t, account)
  - require.Equal(t, account.Balance, value)
  + require.True(t, BigEqual(account.Balance, value))
  }
  }
  @@ -61,3 +61,11 @@ func TestCode(t *testing.T) {
  require.Equal(t, codeHash, common.BytesToHash(crypto.Keccak256(code)))
  }
  }
  +
  +func BigEqual(a, b *big.Int) bool {
  + if a == nil || b == nil {
  + return a == b
  + } else {
  + return a.Cmp(b) == 0
  + }
  +}
  