Nighly build from 2017-06-15 crashes (https://bitcoin.jonasschnelli.ch/build/176)
Nighy build from 2017-06-14 works fine (https://bitcoin.jonasschnelli.ch/build/175)

Relevant commit must be between 228c319a and fbf5d3ba.

```shell
jonasschnelli@Jonass-MBP:~/Documents/bitcoin/bitcoin$ ~/Downloads/bitcoin-0.14.n/bin/bitcoind --regtest
Abort trap: 6
jonasschnelli@Jonass-MBP:~/Documents/bitcoin/bitcoin$ lldb ~/Downloads/bitcoin-0.14.n/bin/bitcoind
(lldb) target create "/Users/jonasschnelli/Downloads/bitcoin-0.14.n/bin/bitcoind"
Current executable set to '/Users/jonasschnelli/Downloads/bitcoin-0.14.n/bin/bitcoind' (x86_64).
(lldb) run --regtest
Process 29763 launched: '/Users/jonasschnelli/Downloads/bitcoin-0.14.n/bin/bitcoind' (x86_64)
Process 29763 stopped
* thread #1, queue = 'com.apple.main-thread', stop reason = signal SIGABRT
    frame #0: 0x00007fff94f74d42 libsystem_kernel.dylib`__pthread_kill + 10
libsystem_kernel.dylib`__pthread_kill:
->  0x7fff94f74d42 <+10>: jae    0x7fff94f74d4c            ; <+20>
    0x7fff94f74d44 <+12>: movq   %rax, %rdi
    0x7fff94f74d47 <+15>: jmp    0x7fff94f6dcaf            ; cerror_nocancel
    0x7fff94f74d4c <+20>: retq   
(lldb) bt
* thread #1, queue = 'com.apple.main-thread', stop reason = signal SIGABRT
  * frame #0: 0x00007fff94f74d42 libsystem_kernel.dylib`__pthread_kill + 10
    frame #1: 0x00007fff950625bf libsystem_pthread.dylib`pthread_kill + 90
    frame #2: 0x00007fff94eda4bb libsystem_c.dylib`__abort + 140
    frame #3: 0x00007fff94edad7e libsystem_c.dylib`__stack_chk_fail + 205
    frame #4: 0x0000000100270364 bitcoind`___lldb_unnamed_symbol4989$$bitcoind + 228
    frame #5: 0x0000000100046660 bitcoind`___lldb_unnamed_symbol475$$bitcoind + 32
    frame #6: 0x0000000100003be9 bitcoind`___lldb_unnamed_symbol1$$bitcoind + 2665
    frame #7: 0x00000001000042a1 bitcoind`___lldb_unnamed_symbol2$$bitcoind + 49
    frame #8: 0x00007fff94e46235 libdyld.dylib`start + 1
(lldb) 
```
WriteLE32(ent32 + 8 * iter, r1);
            WriteLE32(ent32 + 8 * iter + 4, r2);
        }
#else
        uint64_t r1, r2, r3, r4;
        __asm__ volatile (".byte 0x48, 0x0f, 0xc7, 0xf0, " 
                                "0x48, 0x0f, 0xc7, 0xf3, " 
                                "0x48, 0x0f, 0xc7, 0xf1, " 
                                "0x48, 0x0f, 0xc7, 0xf2; " 
                          "setc %4" :
                          "=a"(r1), "=b"(r2), "=c"(r3), "=d"(r4), "=q"(ok) :: "cc");
        if (!ok) return false;
        WriteLE64(ent32, r1);
        WriteLE64(ent32 + 8, r2);
        WriteLE64(ent32 + 16, r3);
        WriteLE64(ent32 + 24, r4);
#endif
        return true;
    }
#endif
    return false;
}
void RandAddSeed()
{
    
    int64_t nCounter = GetPerformanceCounter();
    RAND_add(&nCounter, sizeof(nCounter), 1.5);
    memory_cleanse((void*)&nCounter, sizeof(nCounter));
}
static void RandAddSeedPerfmon()