Re-forbid underscore in positional parameters
Underscores were added to numeric literals in faff8f8e47. This change
also affected the positional parameters (e.g., $1) rule, which uses
the same production for its digits. But this did not actually work,
because the digits for parameters are proces
Re-forbid underscore in positional parameters
Underscores were added to numeric literals in faff8f8e47. This change
also affected the positional parameters (e.g., $1) rule, which uses
the same production for its digits. But this did not actually work,
because the digits for parameters are proces
