packages: Add 'search-patches'.

* gnu/packages.scm (search-patches): New macro.

gnu/packages.scm

@@ -37,6 +37,7 @@
   #:use-module (srfi srfi-35)
   #:use-module (srfi srfi-39)
   #:export (search-patch
+            search-patches
             search-bootstrap-binary
             %patch-path
             %bootstrap-binaries-path
@@ -76,6 +77,11 @@
               (&message (message (format #f (_ "~a: patch not found")
                                          file-name)))))))
 
+(define-syntax-rule (search-patches file-name ...)
+  "Return the list of absolute file names corresponding to each
+FILE-NAME found in %PATCH-PATH."
+  (list (search-patch file-name) ...))
+
 (define (search-bootstrap-binary file-name system)
   "Search the bootstrap binary FILE-NAME for SYSTEM.  Raise an error if not
 found."