Remove "boolean" and "var_boolean" checks from ARI

Remove "boolean" and "var_boolean" checks from ARI

The "boolean" and "var_boolean" checks from ARI seem only to generate
false reports.

Now that gdb is in C++, at least the "boolean" check seems unlikely to
ever generate a true report.

The "var_boolean" check likewise doesn't seem valuable any more --
presumably this refers to some ancient way of doing things in gdb, and
isn't likely to find a bug in the future.

Therefore, this patch removes these two checks.

gdb/ChangeLog
2019-12-13  Tom Tromey  <tromey@adacore.com>

	* contrib/ari/gdb_ari.sh: Remove "boolean" and "var_boolean"
	checks.

Change-Id: Iaf449b51e8182ffa0b9ed25fe688e0ff64a07a67