gdb/doc: some more details in the README file

After some recent discussions on the mailing list, I've made some
changes to the README to (I hope) provide more clarity.

The changes I made are:

  1. Removed the use of a lone 'HOST' on the configure line.  I tried
  this and 'configure' gave me a warning:

    configure: WARNING: you should use --build, --host, --target

  So I don't think this is approved practice any more.  We should
  encourage users to use `--host` instead.

  2. Added and reworded the --host, --target, and --enable-targets
  descriptions in the 'configure options' section.  My goals here are
  to clarify that 'cross-debugging' is really the same as 'remote
  debugging', and also to make it clearer what the defaults are.

  3. Added some additional text to the 'Remote debugging' section
  mentioning that 'remote debugging' is basically the same as 'cross
  debugging', given that we use 'cross-debugging' in the text above.

Reviewed-By: Keith Seitz <keiths@redhat.com>
1 file changed