Should p4-hlir allow arithmetic expressions in instance_count and size expressions?

[jafingerhut]

When trying the mtag-edge.p4 example program from the p4 v1.0.2 and v1.1 specs, p4-graphs and p4-1.1-graphs give error messages when attempting to parse arithmetic operators as part of an expression for instance_count and size expressions. For example, this table definition:

table egress_meter {
    reads {
        standard_metadata.ingress_port : exact;
        mtag.up1 : exact;
    }
    actions {
        meter_pkt;
        _no_op;
    }
    size : PORT_COUNT * PORT_COUNT; // Could be smaller
}

causes the following error messages when you attempt to parse it with p4-graphs / p4-1.1-graphs:

parse error in file /home/andy/p4/andy-tests/mtag-v1.0.2/mtag-edge.p4 at line 188 : Syntax error while parsing at token * (TIMES)
parse error in file /home/andy/p4/andy-tests/mtag-v1.0.2/mtag-edge.p4 at line 188 : Invalid size attribute for table

It is straightforward to work around by replacing the expression with the result, but it would be nicer if the parser could handle this, since it seems to be allowed by the BNF in the spec.