build-system/gnu: Remove the "debug" output when `strip-binaries?' is #f.

* guix/build-system/gnu.scm (gnu-build, gnu-cross-build): Delete "debug"
  from OUTPUTS when STRIP-BINARIES? is false.
* gnu/packages/cross-base.scm (cross-libc): Leave `outputs' unchanged.
  This reverts commit a4627d4.

gnu/packages/cross-base.scm

@@ -251,9 +251,6 @@ XBINUTILS and the cross tool chain."
               #t))
           ,phases))))
 
-    ;; Remove the "debug" output since stripping is disabled.
-    (outputs (delete "debug" (package-outputs glibc)))
-
     (propagated-inputs `(("cross-linux-headers" ,xlinux-headers)))
     (native-inputs `(("cross-gcc" ,xgcc)
                      ("cross-binutils" ,xbinutils)

guix/build-system/gnu.scm

@@ -299,7 +299,9 @@ which could lead to gratuitous input divergence."
                                   ,@(if implicit-inputs?
                                         implicit-inputs
                                         '()))
-                                #:outputs outputs
+                                #:outputs (if strip-binaries?
+                                              outputs
+                                              (delete "debug" outputs))
                                 #:modules imported-modules
                                 #:guile-for-build guile-for-build))
 
@@ -470,7 +472,9 @@ platform."
                                   ,@(if implicit-inputs?
                                         implicit-host-inputs
                                         '()))
-                                #:outputs outputs
+                                #:outputs (if strip-binaries?
+                                              outputs
+                                              (delete "debug" outputs))
                                 #:modules imported-modules
                                 #:guile-for-build guile-for-build))