check for bison binary, not yacc

nunoplopes · nunoplopes · commit 434fae97f240 · 2019-03-16T12:22:44.000-04:00
this fixes compilation with recent bison
diff --git a/acinclude.m4 b/acinclude.m4
@@ -1842,7 +1842,7 @@ dnl
 dnl Search for bison and check it's version
 dnl
 AC_DEFUN([PHP_PROG_BISON], [
-  AC_PROG_YACC
+  AC_CHECK_PROG(YACC, bison, bison)
   LIBZEND_BISON_CHECK
   PHP_SUBST(YACC)
 ])
