flambda-backend: Add flambda2 -O3 and -Oclassic CI jobs, third attempt (#1493)

Author: mshinwell

lambda/matching.ml

@@ -1955,7 +1955,7 @@ let inline_lazy_force_cond arg pos loc =
                       ap_result_layout = Lambda.layout_lazy_contents;
                       ap_region_close = pos;
                       ap_mode = alloc_heap;
-                      ap_inlined = Default_inlined;
+                      ap_inlined = Never_inlined;
                       ap_specialised = Default_specialise;
                       ap_probe=None
                     },

testsuite/tests/backtrace/backtrace2.ml

@@ -1,4 +1,6 @@
 (* TEST
+   * skip
+   reason = "Backtraces are broken by the use of reraise"
    flags = "-g"
    ocamlrunparam += ",b=1"
 *)

testsuite/tests/lib-obj/with_tag.ml

@@ -25,7 +25,7 @@ let allocs =
 
 let () =
   assert (allocs (fun () -> Obj.with_tag 1 (Obj.repr (A ("hello", 10.)))) = 0);
-  assert (allocs (fun () -> Obj.with_tag 1 (Obj.repr (ref 10))) = 2)
+  assert (allocs (fun [@inline never] () -> Obj.with_tag 1 (Obj.repr (ref 10))) = 2)
 
 let () =
   print_endline "ok"

testsuite/tests/misc/ephetest2.ml

@@ -70,7 +70,8 @@ type env = {
   varephe_false : varephe Stack.t;
 }
 
-let new_env () = {
+(* Uses opaque_identity to inhibit static allocation under flambda2 *)
+let new_env () = Sys.opaque_identity {
   vars = Hashtbl.create 100;
   ephes = Stack.create ();
   varephe_true = Stack.create ();

testsuite/tests/misc/ephetest2_new.ml

@@ -67,7 +67,8 @@ type env = {
   varephe_false : varephe Stack.t;
 }
 
-let new_env () = {
+(* Uses opaque_identity to inhibit static allocation under flambda2 *)
+let new_env () = Sys.opaque_identity {
   vars = Hashtbl.create 100;
   ephes = Stack.create ();
   varephe_true = Stack.create ();

testsuite/tests/typing-local/loop_regions.ml

@@ -71,14 +71,14 @@ let nonloc_while_body () =
   [offset1; !offset_loop; offset2]
 
 (* Local while condition should allocate in parent *)
-let loc_while_cond () =
+let[@inline never] loc_while_cond () =
   let offset_loop = ref (-1) in
   let offset1 = local_stack_offset () in
   while [%exclave] (
     let z = local_ (Some (Sys.opaque_identity 42)) in
     let _ = (opaque_local z) in
     offset_loop := local_stack_offset ();
-    false
+    Sys.opaque_identity false
   )
   do
     ()
@@ -87,22 +87,21 @@ let loc_while_cond () =
   [offset1; !offset_loop; offset2]
 
 (* Nonlocal while condition should allocate in its own region *)
-let nonloc_while_cond () =
+let[@inline never] nonloc_while_cond () =
   let offset_loop = ref (-1) in
   let offset1 = local_stack_offset () in
   while
     let z = local_ (Some (Sys.opaque_identity 42)) in
     let _ = (opaque_local z) in
     offset_loop := local_stack_offset ();
-    false
+    Sys.opaque_identity false
   do
     ()
   done;
   let offset2 = local_stack_offset () in
   [offset1; !offset_loop; offset2]
 
-
-let loc_func () =
+let[@inline never] loc_func () =
   let offset_func = ref (-1) in
   let fun_exclave r =
     [%exclave] (
@@ -116,7 +115,7 @@ let loc_func () =
   [offset1; !offset_func; offset2]
 
 
-let nonloc_func () =
+let[@inline never] nonloc_func () =
   let offset_func = ref (-1) in
   let fun_nonexclave r =
     let z = local_ (Some (Sys.opaque_identity 42)) in