system-type related trivia.

* lisp/cedet/semantic/bovine/c.el: Test system-type with memq.

* lisp/progmodes/cperl-mode.el (cperl-find-pods-heres, cperl-write-tags):
No recent Emacs supports system-type `emx'.

* lisp/progmodes/ada-xref.el (is-windows): Rename to ada-on-ms-windows.
(ada-command-separator, ada-default-prj-properties)
(ada-find-any-references): Update for above name change.

* lisp/dirtrack.el (dirtrack-directory-function)
(dirtrack-canonicalize-function):
* lisp/filecache.el (file-cache-completion-ignore-case)
(file-cache-case-fold-search, file-cache-ignore-case):
* lisp/term.el (serial-port-is-file-p): Cosmetic change.

* lisp/emulation/viper-init.el (viper-ms-style-os-p): Doc fix.
Remove non-existent `windows-95' system-type.
* lisp/dired.el (dired-chown-program): Remove non-existent `linux'
system-type.

* lisp/locate.el: Comment.

2 files changed, 8 insertions, 7 deletions

diff --git a/lisp/progmodes/ada-xref.el b/lisp/progmodes/ada-xref.el
index ceda645e682..36e297182cf 100644
--- a/lisp/progmodes/ada-xref.el
+++ b/lisp/progmodes/ada-xref.el
@@ -167,7 +167,7 @@ This has the same syntax as in the project file (with variable substitution)."
 Otherwise, ask the user for the name of the project file to use."
   :type 'boolean :group 'ada)
 
-(defconst is-windows (memq system-type (quote (windows-nt)))
+(defconst ada-on-ms-windows (memq system-type '(windows-nt))
   "True if we are running on Windows.")
 
 (defcustom ada-tight-gvd-integration nil
@@ -222,7 +222,7 @@ Used to go back to these positions.")
 On Windows systems using `cmdproxy.exe' as the shell,
 we need to use `/d' or the drive is never changed.")
 
-(defvar ada-command-separator (if is-windows " && " "\n")
+(defvar ada-command-separator (if ada-on-ms-windows " && " "\n")
   "Separator to use between multiple commands to `compile' or `start-process'.
 `cmdproxy.exe' doesn't recognize multiple-line commands, so we have to use
 \"&&\" for now.")
@@ -768,7 +768,7 @@ is non-nil, prompt the user to select one.  If none are found, return
      'comp_opt        ada-prj-default-comp-opt
      'cross_prefix    ""
      'debug_cmd       (concat ada-prj-default-debugger
-			      " ${main}" (if is-windows ".exe")) ;; FIXME: don't need .exe?
+			      " ${main}" (if ada-on-ms-windows ".exe")) ;; FIXME: don't need .exe?
      'debug_post_cmd  (list nil)
      'debug_pre_cmd   (list (concat ada-cd-command " ${build_dir}"))
      'gnatmake_opt    ada-prj-default-gnatmake-opt
@@ -782,7 +782,7 @@ is non-nil, prompt the user to select one.  If none are found, return
      'make_cmd        (list ada-prj-default-make-cmd) ;; FIXME: should not a list
      'obj_dir         (list ".")
      'remote_machine  ""
-     'run_cmd         (list (concat "./${main}" (if is-windows ".exe")))
+     'run_cmd         (list (concat "./${main}" (if ada-on-ms-windows ".exe")))
      ;; FIXME: should not a list
      ;; FIXME: don't need .exe?
      'src_dir         (list ".")
@@ -1016,7 +1016,7 @@ existing buffer `*gnatfind*', if there is one."
   ;;  processed (gnatfind \"+\":...).
   (let* ((quote-entity
 	  (if (= (aref entity 0) ?\")
-	      (if is-windows
+	      (if ada-on-ms-windows
 		  (concat "\\\"" (substring entity 1 -1) "\\\"")
 		(concat "'\"" (substring entity 1 -1) "\"'"))
 	    entity))
diff --git a/lisp/progmodes/cperl-mode.el b/lisp/progmodes/cperl-mode.el
index fca09145839..6f8c1261510 100644
--- a/lisp/progmodes/cperl-mode.el
+++ b/lisp/progmodes/cperl-mode.el
@@ -3803,7 +3803,8 @@ the sections using `cperl-pod-head-face', `cperl-pod-face',
 						  indentable t))
 	    ;; Need to remove face as well...
 	    (goto-char min)
-	    (and (eq system-type 'emx)
+	    ;; 'emx not supported by Emacs since at least 21.1.
+	    (and (featurep 'xemacs) (eq system-type 'emx)
 		 (eq (point) 1)
 		 (let ((case-fold-search t))
 		   (looking-at "extproc[ \t]")) ; Analogue of #!
@@ -7038,7 +7039,7 @@ Use as
   (or topdir
       (setq topdir default-directory))
   (let ((tags-file-name "TAGS")
-	(case-fold-search (eq system-type 'emx))
+	(case-fold-search (and (featurep 'xemacs) (eq system-type 'emx)))
 	xs rel tm)
     (save-excursion
       (cond (inbuffer nil)		; Already there