[PATCH, doc]: Rename Index node to prevent file collision

[Michael Hope <michael.hope@linaro.org>]

Hi there.  This patch renames the 'Index' node in the GDB end user documentation to 'GDB Index'
to prevent generating HTML filenames that differ only in case.

makeinfo generates a HTML file per node and uses the node name as the filename.  It also generates
a top level 'index.html'.  This causes problems in Windows as 'index.html' and 'Index.html' differ
only in case.

'GDB Index' matches the binutils style of using 'AS Index' and similar for the different tools.
makeinfo displays the node name to the end user in the window title so you can't use names like
'Index_'.

OK for trunk?

-- Michael

2012-06-14  Michael Hope  <michael.hope@linaro.org>

        * gdb.texinfo (GDB Index): Rename 'Index' to 'GDB Index'.

--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -182,7 +182,7 @@ software in general.  We will miss him.
  * Copying::                    GNU General Public License says
                                  how you can copy and share GDB
  * GNU Free Documentation License::  The license for this documentation
-* Index::                       Index
+* GDB Index::                   GDB Index
  @end menu

  @end ifnottex
@@ -1779,7 +1779,7 @@ and @code{show} to inquire about the state of your program, or the state
  of @value{GDBN} itself.  Each command supports many topics of inquiry; this
  manual introduces each of them in the appropriate context.  The listings
  under @code{info} and under @code{show} in the Index point to
-all the sub-commands.  @xref{Index}.
+all the sub-commands.  @xref{GDB Index}.

  @c @group
  @table @code
@@ -40390,8 +40390,8 @@ A string in the constant pool is zero-terminated.
  @appendix GNU Free Documentation License
  @include fdl.texi

-@node Index
-@unnumbered Index
+@node GDB Index
+@unnumbered GDB Index

  @printindex cp