proc/gdbserial: inline (*gdbThread).stepInstruction (#2155)
proc/gdbserial: inline (*gdbThread).stepInstruction (#2155)

(*gdbThread).StepInstruction is a single call to stepInstruction so
inline it.
aarzilli/delve,go-delve/delve,go-delve/delve,aarzilli/delve,aarzilli/delve,aarzilli/delve,go-delve/delve,go-delve/delve,go-delve/delve