Re: (ITS#8819) LMDB seg fault with MDB_DUPSORT on -O3

[h . b . furuseth]

Looks like another type aliasing problem to me.  The data is accessed
through an MDB_page* variable.  This tells the compiler that the data
is word-aligned, like struct MDB_page.  Fix: Use a void/char pointer,
don't lie to the compiler.