The CS_LEX_SPACE command flag causes explicit tWSPACE tokens to be yielded,
instead of silently consuming whitespace between other tokens. This can be
useful for whitespace-sensitive CS_OWN commands.
The db_cmd_radix variable is exposed for commands to explicitly set a radix
for use during db_lex() tNUMBER lexing. This overrides the user-specific
db_radix as well as any auto-sensing.
Both of these additions are scoped to the specific command and reset on
return. Commands cannot themselves scope flags like this because a trap may
abort them prior to cleanup; and a lot of ddb(4) lexing state and options