Rename to...
(yypstate_init, yypstate, struct yypstate, yypush_parse): ... these and update all uses.
(b4_yyssa, b4_yyerror_range, yypstate_init): Rename pv to yyps.
(yypush_parse): Rename yypvars argument to yyps and remove redundant
local pv.
(yypstate_init, yypush_parse): Declare in Bison-generated header file.
* tests/calc.at (_AT_DATA_CALC_Y): Use newly named functions.