* defined a (base-rtd) procedure that returns the base rtd.

* added:
   src/ikarus.singular-objects.ss

src/ikarus.compiler.ss

@@ -171,6 +171,7 @@
     [$fp-at-base        0   pred]
     [$current-frame     0   value]
     [$arg-list          0   value]
+    [base-rtd           0   value]
     [$seal-frame-and-call 1  tail]
     [$frame->continuation 1 value]
     [$interrupted?       0   pred]
@@ -2017,7 +2018,7 @@
     (case op
       [(fixnum? flonum? bignum? immediate? boolean? char? vector? string? procedure?
         null? pair? not cons eq? vector symbol? error eof-object eof-object? 
-        void $unbound-object? $code? $forward-ptr? bwp-object?
+        void base-rtd $unbound-object? $code? $forward-ptr? bwp-object?
         pointer-value top-level-value car cdr list* list $record
         port? input-port? output-port?
         $make-port/input $make-port/output $make-port/both
@@ -3188,6 +3189,7 @@
       [(arg-list)           (mem 32 pcr)]
       [(engine-counter)     (mem 36 pcr)]
       [(interrupted)        (mem 40 pcr)]
+      [(base-rtd)           (mem 44 pcr)]
       [else (error 'pcb-ref "invalid arg ~s" x)])))
 
 (define do-warn
@@ -4041,6 +4043,8 @@
                      (f (cdr arg*) (fxadd1 idx)))])]))]
      [($current-frame)
       (list* (movl (pcb-ref 'next-continuation) eax) ac)]
+     [(base-rtd)
+      (list* (movl (pcb-ref 'base-rtd) eax) ac)]
      [($arg-list)
       (list* (movl (pcb-ref 'arg-list) eax) ac)]
      [($seal-frame-and-call) 

src/ikarus.singular-objects.ss

@@ -0,0 +1,7 @@
+
+(library (ikarus singular-objects)
+  (export base-rtd)
+  (import 
+    (rename (ikarus) (base-rtd sys:base-rtd)))
+  (define (base-rtd) (sys:base-rtd)))
+

src/makefile.ss

@@ -21,7 +21,8 @@
     ;;;  an error (which may lead to the infamous Error: Error: 
     ;;;  Error: Error: Error: Error: Error: Error: Error: ...).
     ;;;
-    '("ikarus.handlers.ss"
+    '("ikarus.singular-objects.ss"
+      "ikarus.handlers.ss"
       "ikarus.multiple-values.ss"
       "ikarus.control.ss"
       "ikarus.collect.ss"
@@ -536,6 +537,7 @@
       [collect                s]
       [do-stack-overflow      s]
       [syntax-dispatch        s]
+      [base-rtd               s i]
       ))