The linker flags for setting the compatibility and current versions of
libraries on Darwin are set for the supported Fortran compilers.
Set CMAKE_Fortran_CREATE_SHARED_LIBRARY for the NAG Fortran compiler to
have no space after <SONAME_FLAG> so the NAG compiler can parse the
argument correctly.
Use the "-X -v" flag to the Absoft front-end to pass "-v" to the gcc it
invokes under the hood. Teach CMakeParseImplicitLinkInfo to exclude
linker version lines from consideration as link lines. Fix parsing of
Sun's linker search path option "-Y..." to avoid conflict with the Mac
linker option "-Y<num>".