Problem: integer constants in builtins get interpreted as instructions

[yrashk]

When adding a constant to a "builtins" (see builtins! and handle_builtins! macros) file like this:

$FIXATTRLEN : 20.

When trying to use it, get the following error:

PumpkinDB> $FIXATTRLEN.
Error: "Unknown instruction: 20" 0x03823230 0x02

However, using binary syntax works fine.

$FIXATTRLEN : 0x14.

works as expected:

PumpkinDB> $FIXATTRLEN.
0x14