kernel: multi-expression body for $vau/$lambda + 5 tests [nothing]

:body slot holds a LIST of forms now (was single expression). New
knl-eval-body in eval.sx evaluates each form in sequence, returning
the last. $vau and $lambda accept (formals env-param body...) /
(formals body...). No $sequence dependency. 223 tests total.

lib/kernel/runtime.sx

@@ -40,13 +40,13 @@
   (fn
     (args dyn-env)
     (cond
-      ((not (= (length args) 3))
-        (error "$vau: expects (formals env-param body)"))
+      ((< (length args) 3)
+        (error "$vau: expects (formals env-param body...)"))
       (:else
         (let
           ((formals (first args))
             (eparam-raw (nth args 1))
-            (body (nth args 2)))
+            (body-forms (rest (rest args))))
           (cond
             ((not (knl-formals-ok? formals))
               (error "$vau: formals must be a list of symbols"))
@@ -56,7 +56,7 @@
               (kernel-make-user-operative
                 formals
                 (knl-eparam-sentinel eparam-raw)
-                body
+                body-forms
                 dyn-env))))))))
 
 (define
@@ -70,17 +70,21 @@
   (fn
     (args dyn-env)
     (cond
-      ((not (= (length args) 2))
-        (error "$lambda: expects (formals body)"))
+      ((< (length args) 2)
+        (error "$lambda: expects (formals body...)"))
       (:else
         (let
-          ((formals (first args)) (body (nth args 1)))
+          ((formals (first args)) (body-forms (rest args)))
           (cond
             ((not (knl-formals-ok? formals))
               (error "$lambda: formals must be a list of symbols"))
             (:else
               (kernel-wrap
-                (kernel-make-user-operative formals :knl-ignore body dyn-env)))))))))
+                (kernel-make-user-operative
+                  formals
+                  :knl-ignore
+                  body-forms
+                  dyn-env)))))))))
 
 (define
   kernel-lambda-operative