Update for AMD64. repocopied from i386-elf/crt1.c.  Deal with regparm argument passing rather than stack based args.  The kernel passes the base of the argument/env vector in %rdi (arg1).
Update for AMD64. repocopied from i386-elf/crt1.c.  Deal with regparm
argument passing rather than stack based args.  The kernel passes the
base of the argument/env vector in %rdi (arg1).

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase