Support cross-testing (version 2)

[Joseph S. Myers]

On Tue, 23 Oct 2012, Roland McGrath wrote:

> After that, cross-test-wrapper is a poor name.  It's really just an
> additional prefix for running test programs and doesn't intrinsically have
> anything to do with cross-ness.  Unfortunately we're already using the most
> obvious name, run-program-prefix, for an internal variable.
> 
> It's also not really right to use the same thing for running built binaries
> directly and for running "env ...".  If it's an emulator, then it can only
> run the host binaries, not some "env" binary that doesn't necessarily exist.
> Using it for "sh -c ..." is even worse.

How about test-wrapper and test-wrapper-env (to run a newly built program, 
to run a newly built program with environment variables)?  With the 
default of test-wrapper-env being "$(test-wrapper) env".  The 
run-built-tests default when cross-compiling would then depend on whether 
$(test-wrapper) is empty or not.

-- 
Joseph S. Myers
joseph@codesourcery.com