Fix mi-nonstop.exp with extended-remote

Testing with "maint set target-non-stop on" makes mi-nonstop.exp run
with the extended-remote board.  That reveals that mi-nonstop.exp is
using the wrong predicate to check for "using remote protocol".

This is not visible today because non-stop tests all fail to run with
extended-remote board, because they spawn gdb and then do "set
non-stop on".  However, with that board, gdb connects to the gdbserver
from within mi_gdb_start, and changing non-stop when already connected
doesn't work.  Fix that by instead enabling non-stop mode on gdb's
command line.

gdb/testsuite/ChangeLog:
2015-11-30  Pedro Alves  <palves@redhat.com>

	* gdb.mi/mi-nonstop.exp: Append "set non-stop on" to GDBFLAGS
	instead of issuing "-gdb-set non-stop 1" after starting gdb.
	Use mi_is_target_remote instead of checking "is_remote target".
	* lib/gdb.exp (gdb_is_target_remote): Rename to ...
	(gdb_is_target_remote_prompt): ... this, and add 'prompt_regexp'
	parameter.
	(gdb_is_target_remote): Reimplement.
	* lib/mi-support.exp (mi_is_target_remote): New procedure.

1 files changed, 7 insertions, 4 deletions

diff --git a/gdb/testsuite/gdb.mi/mi-nonstop.exp b/gdb/testsuite/gdb.mi/mi-nonstop.exp
index d2cb95b..50cf497 100644
--- a/gdb/testsuite/gdb.mi/mi-nonstop.exp
+++ b/gdb/testsuite/gdb.mi/mi-nonstop.exp
@@ -23,8 +23,12 @@ load_lib mi-support.exp
 set MIFLAGS "-i=mi"
 
 gdb_exit
-if {[mi_gdb_start]} {
-    continue
+
+save_vars { GDBFLAGS } {
+    append GDBFLAGS " -ex \"set non-stop on\""
+    if {[mi_gdb_start]} {
+	continue
+    }
 }
 
 proc mi_nonstop_resume { command test } {
@@ -49,7 +53,6 @@ if {[gdb_compile_pthreads "$srcdir/$subdir/$srcfile" $binfile executable $option
 mi_gdb_reinitialize_dir $srcdir/$subdir
 mi_gdb_load $binfile
 
-mi_gdb_test "-gdb-set non-stop 1" ".*"
 mi_gdb_test "-gdb-set mi-async 1" ".*"
 mi_detect_async
 
@@ -132,7 +135,7 @@ mi_gdb_test "-thread-select 2" "\\^done.*" "select first worker thread"
 mi_gdb_test "-gdb-set --thread 3 variable exit_first_thread=1" ".*\\^done" "ask the second thread to exit"
 
 set test "wait for thread exit"
-if { [is_remote target] } {
+if { [mi_is_target_remote] } {
     # The remote protocol doesn't have support for thread exit
     # notifications.
     unsupported $test