Factor the generation of the (integral) tables bw yacc.c and lalr1.cc.
* data/lalr1.cc (b4_tables_map): Move to...
* data/bison.m4: here.
Update the comment for yytable during the flight.
(b4_tables_declare, b4_tables_define): New.
* data/lalr1.cc: Use them.
* data/c.m4 (b4_table_define): New.
* data/yacc.c: Use b4_tables_define instead of output the tables
by hand.
* tests/regression.at (Web2c Actions): Adjust the expected output,
the order of the tables changed.