cmp: inl: tighter type bounds for inlined arguments

Also improve PRECISE-LOC-LISP-TYPE to AND both types instead of picking the "new
type".

src/cmp/cmpbackend-cxx/cmpc-arg-inl.lsp

@@ -132,19 +132,15 @@
 
 (defun emit-inline-form (form forms)
   (with-c1form-env (form form)
-    (case (c1form-name form)
-      (LOCATION
-       (precise-loc-lisp-type (c1form-arg 0 form) (c1form-primary-type form)))
-      (VARIABLE
-       (emit-inlined-variable form forms))
-      (SETQ
-       (emit-inlined-setq form forms))
-      (PROGN
-       (emit-inlined-progn form forms))
-      (VALUES
-       (emit-inlined-values form forms))
-      (t
-       (emit-inlined-temp-var form (c1form-primary-type form) :object)))))
+    (precise-loc-lisp-type
+     (case (c1form-name form)
+       (LOCATION (c1form-arg 0 form) )
+       (VARIABLE (emit-inlined-variable form forms))
+       (SETQ     (emit-inlined-setq form forms))
+       (PROGN    (emit-inlined-progn form forms))
+       (VALUES   (emit-inlined-values form forms))
+       (t        (emit-inlined-temp-var form t :object)))
+     (c1form-primary-type form))))
 
 ;;;
 ;;; inline-args:

src/cmp/cmplocs.lsp

@@ -155,9 +155,10 @@
 ;;;     CL-VA-ARG
 
 (defun precise-loc-lisp-type (loc new-type)
-  (if (subtypep (loc-lisp-type loc) new-type)
-      loc
-      `(the ,new-type ,loc)))
+  (let ((loc-type (loc-lisp-type loc)))
+    (if (subtypep loc-type new-type)
+        loc
+        `(the ,(type-and loc-type new-type) ,loc))))
 
 (defun loc-in-c1form-movable-p (loc)
   "A location that is in a C1FORM and can be moved"