[gdb/testsuite] Remove superfluous 3rd argument from gdb_test call

[gdb/testsuite] Remove superfluous 3rd argument from gdb_test call

There's a pattern:
...
gdb_test <command> <pattern> <command>
...
that can be written shorter as:
...
gdb_test <command> <pattern>
...

Detect this pattern in proc gdb_test:
...
     global gdb_prompt
     upvar timeout timeout

     if [llength $args]>2 then {
 	set message [lindex $args 2]
+	if { $message == [lindex $args 0] } {
+	    error "HERE"
+	}
     } else {
 	set message [lindex $args 0]
     }
...
and fix all occurences in gdb.ada.

Tested on x86_64-linux.

gdb/testsuite/ChangeLog:

2019-10-31  Tom de Vries  <tdevries@suse.de>

	* gdb.ada/array_bounds.exp: Drop superfluous 3rd argument to gdb_test.
	* gdb.ada/array_subscript_addr.exp: Same.
	* gdb.ada/arrayidx.exp: Same.
	* gdb.ada/arrayparam.exp: Same.
	* gdb.ada/arrayptr.exp: Same.
	* gdb.ada/boolean_expr.exp: Same.
	* gdb.ada/call_pn.exp: Same.
	* gdb.ada/complete.exp: Same.
	* gdb.ada/fixed_cmp.exp: Same.
	* gdb.ada/fun_addr.exp: Same.
	* gdb.ada/funcall_param.exp: Same.
	* gdb.ada/interface.exp: Same.
	* gdb.ada/mod_from_name.exp: Same.
	* gdb.ada/null_array.exp: Same.
	* gdb.ada/packed_array.exp: Same.
	* gdb.ada/packed_tagged.exp: Same.
	* gdb.ada/print_chars.exp: Same.
	* gdb.ada/print_pc.exp: Same.
	* gdb.ada/ptype_arith_binop.exp: Same.
	* gdb.ada/ptype_field.exp: Same.
	* gdb.ada/ptype_tagged_param.exp: Same.
	* gdb.ada/rec_return.exp: Same.
	* gdb.ada/ref_tick_size.exp: Same.
	* gdb.ada/str_ref_cmp.exp: Same.
	* gdb.ada/taft_type.exp: Same.
	* gdb.ada/tagged.exp: Same.
	* gdb.ada/type_coercion.exp: Same.
	* gdb.ada/uninitialized_vars.exp: Same.

Change-Id: Ibb84a41573c7f21295f3fd42da9b96534205c5c4