Entry in wrong position in etc/PROBLEMS

[Po Lu]

On master, this entry is under "X runtime problems":

*** Link-time optimization with clang doesn't work on Fedora 20.

As of May 2014, Fedora 20 has broken LLVMgold.so plugin support in clang
(tested with clang-3.4-6.fc20) - 'clang --print-file-name=LLVMgold.so'
prints 'LLVMgold.so' instead of full path to plugin shared library, and
'clang -flto' is unable to find the plugin with the following error:

/bin/ld: error: /usr/bin/../lib/LLVMgold.so: could not load plugin library:
/usr/bin/../lib/LLVMgold.so: cannot open shared object file: No such file
or directory

The only way to avoid this is to build your own clang from source code
repositories, as described at http://clang.llvm.org/get_started.html.

I fail to see how this is related to X-Windows, and it should probably
be moved somewhere else.

Thanks.