Possible change to gen* for splits

[Richard Kenner]

    (define_insn_and_split "name"
      ...normal insn...
      [split pattern]
      "split condition"
      "split preparation statements"
    ) 

I like this idea.

    I'd also like it to grok "* condition" for the split condition, which
    means "append condition to whatever condition was in the insn" so that
    the common case of:

I like this idea too, but don't like using '*' since it has other meanings
in the MD file already. How about '|' or '^'?