Cygwin: replace all fgrep' with grep -F'

Unfortunately fgrep is now deprecated in a very pushy way.
Make sure to use grep -F instead all around, even in docs
and comments/

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>

winsup/cygwin/include/cygwin/version.h

@@ -530,9 +530,9 @@ details. */
 
    The mkvers.sh script at the top level produces a .cc file which initializes
    a cygwin_version structure based on the above version information and
-   creates a string table for grepping via "fgrep '%%%' cygwinwhatever.dll"
+   creates a string table for grepping via "grep -F '%%%' cygwinwhatever.dll"
    if you are using GNU grep.  Otherwise you may want to do a
-   "strings cygwinwhatever.dll | fgrep '%%%'" instead.
+   "strings cygwinwhatever.dll | grep -F '%%%'" instead.
 
    This will produce output such as:
 

winsup/cygwin/linux-locale-helpers/fetch-lc_messages-from-linux.c

@@ -150,7 +150,7 @@ main ()
   char name[32], *c;
   FILE *pp;
 
-  pp = popen ("locale -a | grep -a '_' | fgrep -v .", "r");
+  pp = popen ("locale -a | grep -a '_' | grep -F -v .", "r");
   if (!pp)
     {
       perror ("popen failed");

winsup/cygwin/linux-locale-helpers/fetch-lc_time_era-from-linux.c

@@ -218,7 +218,7 @@ main ()
   char name[32], *c;
   FILE *pp;
 
-  pp = popen ("locale -a | grep -a '_' | fgrep -v .", "r");
+  pp = popen ("locale -a | grep -a '_' | grep -F -v .", "r");
   if (!pp)
     {
       perror ("popen failed");

winsup/doc/faq-programming.xml

@@ -380,7 +380,7 @@ cygexec, you can find them with a script like this:
 <screen>
 #!/bin/sh
 cd /bin; for f in `find . -type f -name '*.exe'`; do
-	cygcheck $f | (fgrep -qi cygwin1.dll || echo $f)
+	cygcheck $f | (grep -Fqi cygwin1.dll || echo $f)
 done
 </screen>
 

winsup/doc/xidepend

@@ -12,7 +12,7 @@ fi
 for f in "$@"
 do
 	f=`basename "$f"`
-	if fgrep -q 'xi:include' "$f"
+	if grep -F -q 'xi:include' "$f"
 	then
 		# This file uses XIncludes.  Let's chase its deps recursively.
 		base=`basename "$f" .xml`