Users might define an OUTPUT_DIRECTORY containing $<CONFIG>. Copying the byproducts works fine, but for
the imported location we need to replace
the genex. This is possible, since in
single config mode we know the config,
and in multi config mode we know the
config for the _CONFIG variants of IMPORTED_LOCATION.
Users might define an OUTPUT_DIRECTORY containing
$<CONFIG>. Copying the byproducts works fine, but for the imported location we need to replace the genex. This is possible, since in single config mode we know the config, and in multi config mode we know the config for the_CONFIGvariants of IMPORTED_LOCATION.Fixes #453