Adjust MI to $inferior_spawn_id

Rather than trying to determine where (which spawn id) the inferior
output comes out from, which depends on e.g., remote that supports
file i/o remote protocol extension, vs remote that sends inferior
output through a separate $inferior_spawn_id, vs native debugging,
which sends output through $gdb_spawn_id, vs native debugging with a
test that uses "separate-inferior-tty" (like mi-console.exp does),
always expect inferior output from both $inferior_spawn_id and
$gdb_spawn_id.

mi-console.exp itself already copes with different possible outputs in
a similar way:

 # Combine both outputs in a single pattern.
 set output "($semihosted_output|$native_output)"

Fixes:

 FAIL: gdb.mi/mi-console.exp: Testing console output inferior output (timeout)

when testing against local gdbserver with gdb,noinferiorio removed
from the board file.

gdb/testsuite/ChangeLog:
2015-07-29  Pedro Alves  <palves@redhat.com>

	* lib/mi-support.exp (mi_inferior_spawn_id): Delete.
	(default_mi_gdb_start): Set inferior_spawn_id instead of
	mi_inferior_spawn_id.  If $inferior_spawn_id is not set, set it to
	gdb_spawn_id.
	(mi_gdb_test): Always expect inferior output from both
	$inferior_spawn_id and $gdb_spawn_id.

gdb/testsuite/ChangeLog

@@ -1,3 +1,12 @@
+2015-07-29  Pedro Alves  <palves@redhat.com>
+
+	* lib/mi-support.exp (mi_inferior_spawn_id): Delete.
+	(default_mi_gdb_start): Set inferior_spawn_id instead of
+	mi_inferior_spawn_id.  If $inferior_spawn_id is not set, set it to
+	gdb_spawn_id.
+	(mi_gdb_test): Always expect inferior output from both
+	$inferior_spawn_id and $gdb_spawn_id.
+
 2015-07-29  Pedro Alves  <palves@redhat.com>
 
 	* gdb.gdb/selftest.exp (test_with_self): Update comment.  Use

gdb/testsuite/lib/mi-support.exp

@@ -26,7 +26,6 @@ if ![info exists mi_gdb_prompt] then {
     set mi_gdb_prompt "\[(\]gdb\[)\] \r\n"
 }
 
-global mi_inferior_spawn_id
 global mi_inferior_tty_name
 
 set MIFLAGS "-i=mi"
@@ -104,7 +103,7 @@ proc default_mi_gdb_start { args } {
     global gdb_prompt
     global mi_gdb_prompt
     global timeout
-    global gdb_spawn_id
+    global gdb_spawn_id inferior_spawn_id
     global MIFLAGS
 
     gdb_stop_suppressing_tests
@@ -138,15 +137,6 @@ proc default_mi_gdb_start { args } {
 	}
     }
 
-    # Create the new PTY for the inferior process.
-    if { $separate_inferior_pty } {
-	spawn -pty
-	global mi_inferior_spawn_id
-	global mi_inferior_tty_name
-	set mi_inferior_spawn_id $spawn_id
-	set mi_inferior_tty_name $spawn_out(slave,name)
-    }
-
     set res [remote_spawn host "$GDB $INTERNAL_GDBFLAGS $GDBFLAGS $MIFLAGS [host_info gdb_opts]"]
     if { $res < 0 || $res == "" } {
 	perror "Spawning $GDB failed."
@@ -214,9 +204,14 @@ proc default_mi_gdb_start { args } {
 	    warning "Couldn't set the width to 0."
 	}
     }
-    # If allowing the inferior to have its own PTY then assign the inferior
+
-    # its own terminal device here.
+    # Create the new PTY for the inferior process.
     if { $separate_inferior_pty } {
+	spawn -pty
+	global mi_inferior_tty_name
+	set inferior_spawn_id $spawn_id
+	set mi_inferior_tty_name $spawn_out(slave,name)
+
 	send_gdb "102-inferior-tty-set $mi_inferior_tty_name\n"
 	gdb_expect 10 {
 	    -re ".*102\\\^done\r\n$mi_gdb_prompt$" {
@@ -228,6 +223,10 @@ proc default_mi_gdb_start { args } {
 	}
     }
 
+    if {![info exists inferior_spawn_id]} {
+	set inferior_spawn_id $gdb_spawn_id
+    }
+
     mi_detect_async
 
     return 0
@@ -770,12 +769,11 @@ proc mi_gdb_test { args } {
     if { $result == 0 } {
 	if [ info exists ipattern ] {
 	    if { ![target_info exists gdb,noinferiorio] } {
-		if { [target_info gdb_protocol] == "remote"
+		global gdb_spawn_id inferior_spawn_id
-		    || [target_info gdb_protocol] == "extended-remote"
-		    || [target_info protocol] == "sim"} {
 
+		set sid "$inferior_spawn_id $gdb_spawn_id"
 		gdb_expect {
-			-re "$ipattern" {
+		    -i "$sid" -re "$ipattern" {
 			pass "$message inferior output"
 		    }
 		    timeout {
@@ -783,18 +781,6 @@ proc mi_gdb_test { args } {
 			set result 1
 		    }
 		}
-		} else {
-		    global mi_inferior_spawn_id
-		    expect {
-			-i $mi_inferior_spawn_id -re "$ipattern" {
-			    pass "$message inferior output"
-			}
-			timeout {
-			    fail "$message inferior output (timeout)"
-			    set result 1
-			}
-		    }
-		}
 	    } else {
 		unsupported "$message inferior output"
 	    }