Feature parity with GDBINIT

[zachriggle]

https://github.com/gdbinit/Gdbinit/blob/master/gdbinit

• init - Run program and break on _init
• start - Run program and break on _start
• sstart - Run program and break on __libc_start_main
• main - Run program and break on main
• argv - Show argv
• stack - Print backtrace
• frame - Show info {frame, args, locals}
• lib(s) - Display shared libraries
• go - Step one instruction
  (Windbg compatibility of go is favored)
• n - Step N instructions
• pret - Finish frame, print return value
  Won't implement, use the finish command.
• stepo - Step over calls
• stepoh - Uses hardware breakpoints
• skip - Skip over N instructions
• nop - Nop out address
• null - Zero out address
• int3 - Patch in an int3 / BKPT at address
• unpatch - Restore original value pre-patch
• entry_point - Prints entrypoint

Interesting settings:

• set arm show-opcode-bytes 1

Useful aliases:

• bl / bpl - List breakpoints
• bp - Breakpoint
• bc / bpc - Clear breakpoint
• be / bpe - Enable breakpoint
• bd / bpd - Disable breakpoint