Use RIP relative addressing to initialize RBP.
Use RIP relative addressing to initialize RBP.

On X86_64, we can use RIP relative addressing to load the address of
the data into RBP, no need to use the traditional get pc. On
X86_64NullSafe we use the old get pc to avoid NUL bytes.
edibledinos/pwnypack,edibledinos/pwnypack