base: Fix broken IPython argument handling
base: Fix broken IPython argument handling

Prior to this changeset, we used to clear sys.argv before entering the
IPython shell. This caused some versions of IPython to crash because
they assume argv[0] to exist. The correct way of overriding the
arguments passed to IPython is to set the argv keyword argument when
initializing the shell.

haowu4682/gem5,haowu4682/gem5,LingxiaoJIA/gem5,LingxiaoJIA/gem5,haowu4682/gem5,LingxiaoJIA/gem5,haowu4682/gem5,LingxiaoJIA/gem5,haowu4682/gem5,LingxiaoJIA/gem5,LingxiaoJIA/gem5,LingxiaoJIA/gem5,haowu4682/gem5,haowu4682/gem5,haowu4682/gem5,haowu4682/gem5