Added x64 function prologue

[N0fix]

Adding x64 function prologues:

55       push rbp
48 89 e5 mov rbp, rsp

55       push rbp
48 89 ec mov rsp, rbp

I found the first one 55 48 89 E5 in a CTF executable. See the executable attached. SMDA is missing the entry point, figured with some debug that it was not finding the prologue. It also avoid the function at EP because it ends with a syscall(exit), and tries to continue disassembling after that. But for now, adding the prologue will do. I assumed the second opcode 55 48 89 EC) should exist too.