dfilter: Allow constants as the first or only argument to min/max

The strategy here is to delay resolving literals to values until
we have looked at the entire argument list.

Also we will try to commute the relation in a comparison if
we do not have a type for the return value of the function,
like any other constant.

Before:

    Filter: max(1,_ws.ftypes.int8) == 1
    dftest: Argument '1' is not valid for max()
    	max(1,_ws.ftypes.int8) == 1
    	    ^

After:

    Filter: max(1,_ws.ftypes.int8) == 1

    Syntax tree:
     0 TEST_ANY_EQ:
       1 FUNCTION(max#2):
         2 FVALUE(1 <FT_INT8>)
         2 FIELD(_ws.ftypes.int8 <FT_INT8>)
       1 FVALUE(1 <FT_INT8>)

    Instructions:
    00000 STACK_PUSH	1 <FT_INT8>
    00001 READ_TREE		_ws.ftypes.int8 <FT_INT8> -> reg#1
    00002 IF_FALSE_GOTO	3
    00003 STACK_PUSH	reg#1
    00004 CALL_FUNCTION	max(reg#1, 1 <FT_INT8>) -> reg#0
    00005 STACK_POP	2
    00006 IF_FALSE_GOTO	8
    00007 ANY_EQ		reg#0 == 1 <FT_INT8>
    00008 RETURN

0 files changed, 0 insertions, 0 deletions