use a flag to signal a stacking filetests instead of peeking at the n…

…ext op.

Preparation for the codegeneration changes where the next op isn't accessible.

op.c

@@ -7342,8 +7342,10 @@ Perl_ck_ftst(pTHX_ OP *o)
 	if ((PL_hints & HINT_FILETEST_ACCESS) && OP_IS_FILETEST_ACCESS(o->op_type))
 	    o->op_private |= OPpFT_ACCESS;
 	if (PL_check[kidtype] == Perl_ck_ftst
-		&& kidtype != OP_STAT && kidtype != OP_LSTAT)
+	        && kidtype != OP_STAT && kidtype != OP_LSTAT) {
 	    o->op_private |= OPpFT_STACKED;
+	    kid->op_private |= OPpFT_STACKING;
+	}
     }
     else {
 #ifdef PERL_MAD

op.h

@@ -284,7 +284,8 @@ Deprecated.  Use C<GIMME_V> instead.
 
 /* Private for OP_FTXXX */
 #define OPpFT_ACCESS		2	/* use filetest 'access' */
-#define OPpFT_STACKED		4	/* stacked filetest, as in "-f -x $f" */
+#define OPpFT_STACKED		4	/* stacked filetest, as "-f" in "-f -x $f" */
+#define OPpFT_STACKING		8	/* stacking filetest, as "-x" in "-f -x $f" */
 
 /* Private for OP_(MAP|GREP)(WHILE|START) */
 #define OPpGREP_LEX		2	/* iterate over lexical $_ */

pp_sys.c

@@ -2914,11 +2914,7 @@ S_try_amagic_ftest(pTHX_ char chr) {
 
 	SPAGAIN;
 
-	next = PL_op->op_next;
-	if (next->op_type >= OP_FTRREAD &&
-	    next->op_type <= OP_FTBINARY &&
-	    next->op_private & OPpFT_STACKED
-	) {
+	if (PL_op->op_private & OPpFT_STACKING) {
 	    if (SvTRUE(tmpsv))
 		/* leave the object alone */
 		return TRUE;