OpenBSD: disable FIND_LIBRARY_USE_LIB64_PATHS

OpenBSD has no multilib paths.
Merge topic 'OpenBSD_no_multilib' into next

956b7190 OpenBSD: disable FIND_LIBRARY_USE_LIB64_PATHS
Remove reference to non-existing test.

The CompileFeatures test was extended instead.
Merge topic 'COMPILE_FEATURES-genex' into next

2e11cbc9 Remove reference to non-existing test.
Features: Add COMPILE_FEATURES generator expression.

Allow setting build properties based on the features available
for a target.  The availability of features is determined at
generate-time by evaluating the link implementation.

Ensure that the <LANG>_STANDARD determined while evaluating
COMPILE_FEATURES in the link implementation is not lower than that
provided by the INTERFACE of the link implementation.  This is
similar to handling of transitive properties such as
POSITION_INDEPENDENT_CODE.
Merge topic 'COMPILE_FEATURES-genex' into next

9b5a1734 Features: Add COMPILE_FEATURES generator expression.