Don't require CST origins in BIR

Changing my mind here, but now that I can produce BIR from Maclina
bytecode, requiring producers to use CST seems overly narrow.

Author: Bike

BIR/cleavir-bir.asd

@@ -10,8 +10,7 @@
   :bug-tracker "https://github.com/s-expressionists/Cleavir/issues"
   :source-control (:git "https://github.com/s-expressionists/Cleavir.git")
   :depends-on (:cleavir-primop :cleavir-set :cleavir-attributes
-                               :acclimation :cleavir-conditions :cleavir-ctype
-               :concrete-syntax-tree)
+                               :acclimation :cleavir-conditions :cleavir-ctype)
   :components
   ((:file "packages")
    (:file "structure" :depends-on ("packages"))

BIR/condition-reporters-english.lisp

@@ -14,13 +14,11 @@
   (let ((origin (conditions:origin condition)))
     (format stream "The derived type of ~:[<nameless datum>~;~:*~a~]
 is ~s~%but is asserted as ~s
-by ~a~:[~; in ~s~]."
+by ~a."
             (name (datum condition))
             (derived-type condition)
             (asserted-type condition)
-            (asserted-by condition)
-            origin
-            (when origin (cst:raw origin)))))
+            (asserted-by condition))))
 
 (defun group-problems (problems)
   ;; Group by subject. Also, put function problems before iblock problems, and

BIR/verify.lisp

@@ -85,11 +85,7 @@ If there are problems, a VERIFICATION-FAILED is signaled. If the verification pr
   (verify-outputs instruction)
   (let ((outputs (outputs instruction)))
     (test (or (null outputs) (not (set:presentp outputs *seen-lists*)))
-          "has shared output list ~a" instruction outputs))
-  ;; verify source info is a CST if it exists
-  (let ((origin (origin instruction)))
-    (test (typep origin '(or null cst:cst))
-          "has invalid origin ~a" instruction origin)))
+          "has shared output list ~a" instruction outputs)))
 
 (defmethod verify-outputs ((instruction writevar))
   (let ((outputs (outputs instruction)))