c: always use YYMALLOC/YYFREE

Reported by Kovalex <kovalex.pro@gmail.com>.
https://lists.gnu.org/r/bug-bison/2020-08/msg00015.html

* data/skeletons/yacc.c: Don't make direct calls to malloc/free.
* tests/calc.at: Check it.

tests/calc.at

@@ -915,6 +915,12 @@ AT_BISON_OPTION_PUSHDEFS([$1])
 
 AT_DATA_CALC_Y([$1])
 AT_FULL_COMPILE(AT_JAVA_IF([[Calc]], [[calc]]), AT_DEFINES_IF([[lex], [main]], [[], []]), [$2], [-Wno-deprecated])
+
+AT_YACC_IF(
+  [# No direct calls to malloc/free.
+  AT_CHECK([[$EGREP '(malloc|free) *\(' calc.[ch] | $EGREP -v 'INFRINGES ON USER NAME SPACE']],
+           [1])])
+
 AT_PUSH_IF([AT_JAVA_IF(
  [# Verify that this is a push parser.
   AT_CHECK_JAVA_GREP([[Calc.java]],

tests/local.at

@@ -390,6 +390,7 @@ AT_LOCATION_TYPE_SPAN_IF(
 
 
 AT_GLR_IF([AT_KEYWORDS([glr])])
+AT_PUSH_IF([AT_KEYWORDS([push])])
 ])# _AT_BISON_OPTION_PUSHDEFS