Cygwin: locale: new script creating linux default codeset mapping

New script creating a mapping table from locale to default codeset
for this locale.  We use that in Cygwin now to generate the own
default codeset mapping based on Linux locale names.

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

winsup/cygwin/linux-locale-helpers/fetch-lc-def-codesets-from-linux

@@ -0,0 +1,48 @@
+#!/bin/bash
+(
+  cat <<-EOF
+	/* This struct of default codesets has been generated by fetching
+	   locale data from a Linux system using $(rpm -q glibc | head -1) on $(date +%F) */
+	struct default_codeset_t
+	{
+	  const char *locale;
+	  const char *codeset;
+	} default_codeset[] =
+	{
+	EOF
+  while read line
+  do
+    locale=$(echo "${line}" | awk '/^locale:/{ print $2; }')
+    if [ -z "${locale}" ]
+    then
+      continue
+    fi
+    # No aliases
+    idx=$(expr index "${locale}" '_')
+    if [ "${idx}" -eq 0 ]
+    then
+      continue
+    fi
+    # No explicit codesets
+    idx=$(expr index "${locale}" '.')
+    if [ "${idx}" -ne 0 ]
+    then
+      continue
+    fi
+    while read line2
+    do
+      codeset=$(echo "${line2}" | awk '/codeset/{ print $3; }')
+      if [ -n "${codeset}" ]
+      then
+	# Translate into internal codeset names. */
+	case "${codeset}" in
+	  BIG5*)	codeset="BIG5";;
+	  *)		;;
+	esac
+	printf "  { \"%s\", \"%s\" },\n" "${locale}" "${codeset}"
+	break
+      fi
+    done
+  done <<<$(locale -av)
+  echo "};"
+) > lc_def_codesets.h