assertion failure with ambiguous LALR compiles
the attached program causes in intermittent assertion failure (~ 10% of the time) when trying to compile the following grammar with the LALR backend:
H_RULE(schar, NOT_IN("()\n\r\\")); /* overlaps digit */
H_RULE(digit, h_ch_range('0', '9'));
H_RULE(digits, CHX(REP(digit,2), REP(digit,1)));
H_RULE(schars, h_many(CHX(schar, digits)));
assertion "action->type == HLR_SHIFT" failed: file "src/backends/lalr.c", line 34, function "follow_transition"