rdmd test-case for pragma(lib) support is incompatible with GDC

[Geod24]

Transferred from: https://issues.dlang.org/show_bug.cgi?id=18421

User @WebDrake reported (2018-02-11 15:21:59 CET):

rdmd_test includes a test-case to ensure that rdmd works for programs that use pragma(lib) to load libraries (see https://issues.dlang.org/show_bug.cgi?id=16978 for the motivation). The correctness sought here is not in any direct handling of pragma(lib), but in ensuring that the way rdmd invokes the D compiler will allow the pragma(lib) call to succeed. Since GDC does not support pragma(lib), the test case will fail when gdmd is used as the D compiler invoked by rdmd. As this is a fault in the compiler rather than rdmd, the test case can simply be disabled when testing with gdmd (since from rdmd's point of view, it suffices to demonstrate that it works with D compilers that support pragma(lib)). However, this is merely a workaround, not a fix. Long-term, the test-case should be re-enabled as soon as GDC support for pragma(lib) is available. This issue has been created in order to ensure that this task does not get forgotten ;-)

Marking as enhancement since we don't do that level of testing at the moment.