BUG#9826  Server crash on schema change ("drop table", "alter table") with NDB

See note on 10948 for detailed explanation.

struct a { void* a; long long b[1]; };

on PPC32 (and 32bit pa risc): 16
on x86: 12

so a malloc(sizeof(void*)+extra_bits) is wrong.

Assuming that the long long is 64 bit aligned as non-aligned 64bit accesses
are rather expensive on ppc.

Thanks to paulus for doing the PPC port of valgrind.
Without which I would no doubt still be trying to find this.