[Bug testsuite/124066] EFFECTIVE_TARGETS flags are not visible to check_compile tests

[rguenth at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=124066

--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
Yep, I'm going to post a POC.