Build fails on Solaris using devkit when X isn't installed

When building on a Solaris machine without having X installed, but using a devkit that provides X, the build still fails with:

ld: warning: file libXrender.so.1: required by /localhome/staffan/mercurial/jdk9-hs-rt/build/solaris-sparcv9-normal-server-release/jdk/lib/sparcv9/libawt_xawt.so, not found

This happens when linking libfontmanager.so which links to libawt_xawt.so. When libawt_xawt.so was linked, the explicit paths to the X libraries in the devkit were put on the command line through the X_LIBS variable. This also added the necessary -R (runtime) paths so that libawt_xawt could find them again at runtime. The problem is that since the machine does not have the libraries in that runtime path, the linker fails to link against libawt_xawt.so.

The solution is to add X_LIBS to the link line of libfontmanager. Only the -L parts of X_LIBS is needed so the -R parts should be filtered out so we do not add unneeded runtime paths to the built library.