[PATCH v2 PR112400]: VAX: ICE in fixup_reorder_chain whilst building gimple_match.cc

[Kalvis Duckmanton]

Hi,

Resubmitting with required certification.

many thanks,

kalvis

   Wrap the limit operand in the casesi pattern in a (use ), to allow
   single_set() to identify it as an RTL expression setting PC.  This
   allows the optimiser to optimise away case statements branching only
   to a basic block

Signed-off-by: Kalvis Duckmanton <kalv...@gmail.com>

diff --git a/gcc/config/vax/vax.md b/gcc/config/vax/vax.md
index c7b3d8a357a8..f23b5b144769 100644
--- a/gcc/config/vax/vax.md
+++ b/gcc/config/vax/vax.md
@@ -2948,7 +2948,7 @@
   "#"
   "reload_completed"
   [(parallel
-     [(match_dup 1)
+     [(use (match_dup 1))
       (set (pc)
 	   (plus:SI (sign_extend:SI
 		      (mem:HI (plus:SI
@@ -2957,8 +2957,8 @@
   "")
 
 (define_insn "*casesi1"
-  [(match_operand:SI 1 "const_int_operand" "n")
+  [(use (match_operand:SI 1 "const_int_operand" "n"))
    (set (pc)
 	(plus:SI (sign_extend:SI
 		   (mem:HI (plus:SI