New testcase arm-disp-step.exp

[Joel Brobecker]

> testsuite/
> 
> 	* gdb.arch/arm-disp-step.exp: New.
> 	* gdb.arch/arm-disp-step.S: New.

Comments below...

> +# Get things started.
> +
> +gdb_exit
> +gdb_start
> +gdb_reinitialize_dir $srcdir/$subdir
> +gdb_load ${binfile}

Use "clean_restart"....

> +# which is in library might be compiled in Thumb.
> +gdb_test "set displaced-stepping off" ""

Use gdb_test_no_output.

> +gdb_test "set displaced-stepping on" ""

Same here.

> +gdb_test_multiple "continue" "continue to test_call" {
> +	-re ".*bl test_call_subr.*" {
> +	    pass "continue to test_call"
> +	}
> +	-re "Displaced stepping is only supported in" {
> +	    xfail $testfile
> +	    return

I'm not sure about the xfail. Why did you decide to use it?
I thought we were supposed to use kfail in this case, since this is
a debugger issue? xfail should be used when the failure is caused
by the debugging environment (compiler bug, missing feature in kernel,
etc).

-- 
Joel