made source_Code_Locations more reliable (sill oncorrect sometimes)

bin/tests/class_macro.slime

@@ -78,4 +78,4 @@
 (define v1 (make-vector3 1 2 3))
 (define v2 (make-vector3 3 2 1))
 
-(v1 scalar-product v2)
+(assert (= (v1 scalar-product v2) 10))

bin/tests/lexical_scope.slime

@@ -0,0 +1,11 @@
+(defun make-counter ()
+  (let ((var 0))
+    (lambda ()
+      (mutate var (+ 1 var))
+      var)))
+
+(define counter (make-counter))
+
+(assert (= (counter) 1))
+(assert (= (counter) 3))
+(assert (= (counter) 3))