Fix i686 build error.

## Overview

The use of `0xFFFFFFF` for the size of a byte array causes the build error:

```
type [268435455]leafPageElement too large
```

This commit changes the byte array size to `0x7FFFFFF`.


## Notes

Thanks to @ernado for reporting the issue and thanks to @mux0r for providing the fix. This change does not affect amd64.

Fixes #195