Since it can be set in the environment when running the test suite,
guard tests which are sensitive to intermediate directory strategy
changes with explicit settings.
Evaluate generator expressions in these properties, as they apply to
`add_test`, `add_custom_command`, and `add_custom_target`.
The `CMAKE_CROSSCOMPILING_EMULATOR` variable's `try_run` behavior occurs
at configure time and so cannot support generator expressions.
A `$<TARGET_FILE:tgt>` generator expression does not cause insertion of
the emulator. Add a test covering this. While at it, extend the test
case to cover executables in a subdirectory. Also make the test
matching expressions more robust to support multiple add_test calls
without mixing them while matching.
Prefix test commands with the CROSSCOMPILING_EMULATOR property
for target executables. This allows test suites to be run on the host
when crosscompiling.
Ben Boeckel
Brad King
Ralf Habacker
Jean-Christophe Fillion-Robin
Matt McCormick