Add the SQLITE_TESTCTRL_BYTEORDER test control to interrogate SQLite's notion
of the processor byte order and whether the byte order is known at compile-time
or determined at run-time.
Add the SQLITE_RUNTIME_BYTEORDER compile-time option to force SQLite to check
the processor byte-order at run-time.  Add additional compile-time byte order
checks for ARM, PPC, and SPARC.