Commit afd7d4ca (Add target property LINK_SEARCH_END_STATIC, 2008-01-31)
defined a property to ensure that static runtime libraries get selected.
Add a property to specify that all libraries whose type is unknown, such
as "-lm", should be assumed static.  Furthermore it assumes that an
option such as "-static" is also used so that no initial -Bstatic is
needed.