Add information about where to find GDB, and warn against --no-debug option

to configure.bat.

nt/ChangeLog

+2007-05-22  Eli Zaretskii  <eliz@gnu.org>
+
+	* INSTALL: Add information about where to find GDB, and warn
+	against --no-debug option to configure.bat.
+
 2007-05-19  Eli Zaretskii  <eliz@gnu.org>
 
 	* INSTALL: Fix URL of EmacsW32 site where building with image

nt/INSTALL

@@ -227,6 +227,9 @@
   To configure Emacs to build with GCC or MSVC, whichever is available,
   simply change to the `nt' subdirectory and run `configure.bat' with no
   options.  To see what options are available, run `configure --help'.
+  Do NOT use the --no-debug option to configure.bat unless you are
+  absolutely sure the produced binaries will never need to be run under
+  a debugger.
 
   N.B.  It is normal to see a few error messages output while configure
   is running, when gcc support is being tested.  These cannot be
@@ -380,7 +383,8 @@
 
   You should be able to debug Emacs using the debugger that is
   appropriate for the compiler you used, namely DevStudio or Windbg if
-  compiled with MSVC, or GDB if compiled with GCC.
+  compiled with MSVC, or GDB if compiled with GCC.  (GDB for Windows
+  is available from the MinGW site, http://www.mingw.org/download.shtml.)
 
   When Emacs aborts due to a fatal internal error, Emacs on Windows
   pops up an Emacs Abort Dialog asking you whether you want to debug