compiler/vm: implement sys:abscond-from special form.

* share/txr/stdlib/asm.tl (abscsr): New instruction.
(op-abscsr): New opcode class, derived from op-retsr.

* share/txr/stdlib/compiler.tl: Handle sys:abscond-from via
comp-return-from method.
(compiler comp-return-from): Handle sys:abscond-from by
switching to abscsr opcode instead of ret pseudo-op.

* vm.c (vm_abscsr): New static function.
(vm_execute): Dispatch ABSCSR opcode.

* vmop.h: Regenerated.

1 files changed, 13 insertions, 12 deletions

diff --git a/vmop.h b/vmop.h
index 065b159e..827340e2 100644
--- a/vmop.h
+++ b/vmop.h
@@ -51,16 +51,17 @@ typedef enum vm_op {
   RETSR = 22,
   RETRS = 23,
   RETRR = 24,
-  CATCH = 25,
-  HANDLE = 26,
-  GETV = 27,
-  GETF = 28,
-  GETL1 = 29,
-  GETVB = 30,
-  GETFB = 31,
-  GETL1B = 32,
-  SETV = 33,
-  SETL1 = 34,
-  BINDV = 35,
-  CLOSE = 36,
+  ABSCSR = 25,
+  CATCH = 26,
+  HANDLE = 27,
+  GETV = 28,
+  GETF = 29,
+  GETL1 = 30,
+  GETVB = 31,
+  GETFB = 32,
+  GETL1B = 33,
+  SETV = 34,
+  SETL1 = 35,
+  BINDV = 36,
+  CLOSE = 37,
 } vm_op_t;