[Hexagon][llvm-objdump] Start a fresh packet at symbol boundaries. (#163466)
Hexagon packets can visually straddle labels when data (e.g. jump
tables) in the text section does not carry end-of-packet bits. In such
cases the next instruction, even at a new symbol, appears to continue
the previous packet.
This patch resets packet state when encountering a new symbol so that
packets at symbol starts are guaranteed to start in their own packet.