[gdb/testsuite] Handle REMOTE_HOST_USERNAME in local-remote-host

Handle REMOTE_HOST_USERNAME in local-remote-host, similar to how that's done for
REMOTE_TARGET_USERNAME in remote-gdbserver-on-localhost.

This helps to keep the home dir clean.

Since the setup makes $build/gdb/testsuite on build unreadable for the remote
host, we run into permission problems for GDB and the data-directory, so fix
this (as was done for gdbserver in gdbserver-base.exp) using file normalize.

Tested on x86_64-linux.

gdb/testsuite/boards/local-remote-host.exp

@@ -22,12 +22,33 @@
 
 # Like local-remote-host-notty, but with readline/editing enabled.
 
-global GDB
-set GDB [file join [pwd] "../gdb"]
+set GDB [file normalize [file join [pwd] "../gdb"]]
 
 set_board_info hostname 127.0.0.1
 
-set_board_info username $env(USER)
+if { [info exists REMOTE_HOST_USERNAME] } {
+    set_board_info username $REMOTE_HOST_USERNAME
+} else {
+    set_board_info username $env(USER)
+}
+
+# Handle separate test account.
+if { [board_info $board username] != $env(USER) } {
+    # We're pretending that some local user account is remote host.
+    # Make things a bit more realistic by restricting file permissions.
+
+    # Make sure remote host can't see files on build.
+    remote_exec build "chmod go-rx $objdir"
+
+    # Make sure build can't see files on remote host.  We can't use
+    # remote_exec host, because we're in the middle of parsing the
+    # host board.
+    remote_exec build \
+	"[board_info $board rsh_prog] \
+		     -l [board_info $board username] \
+			[board_info $board hostname] \
+	chmod go-rx ."
+}
 
 # The ssh key should be correctly set up that you ssh to 127.0.0.1
 # without having to type password.

gdb/testsuite/lib/gdb.exp

@@ -176,7 +176,7 @@ verbose "using GDB = $GDB" 2
 # we're testing a non-installed GDB in the build directory.  Users may
 # also explictly override the -data-directory from the command line.
 if ![info exists GDB_DATA_DIRECTORY] {
-    set GDB_DATA_DIRECTORY "[pwd]/../data-directory"
+    set GDB_DATA_DIRECTORY [file normalize "[pwd]/../data-directory"]
 }
 verbose "using GDB_DATA_DIRECTORY = $GDB_DATA_DIRECTORY" 2