[PATCH] Support (match_operand:MODE) in genpreds

[Paolo Bonzini]

This patch adds a small feature to genpreds, that is

    (match_operand:MODE 0 "predicate")

will call predicate (op, MODE).  This can be useful for example to match 
const_int's in a small range, as in

    (match_operand:QI 0 "immediate_operand")
    (match_operand:QI 0 "const_int_operand")

This patch is pretty safe, but I won't ask to include it in 4.0 if 
branching occurs before review.  So, ok for mainline, whatever version 
number it is associated to?

Paolo