Revert "Genex: Disallow LINKER_LANGUAGE only when used on a static library."

This reverts commit a8c9095d98b18a166989d8d412c3b56db63f029b.
Merge topic 'link-language-static-lib' into next

99591a9 Revert "Genex: Disallow LINKER_LANGUAGE only when used on a static library."
Genex: Disallow LINKER_LANGUAGE only when used on a static library.

For shared libraries and executables, the linker_language is
indepenedent of the linked libraries.
Merge topic 'minor-cleanups' into next

b8dc7fa Genex: Disallow LINKER_LANGUAGE only when used on a static library.