Created attachment 95379 [details]
Patch for configure.ac to fix building against libLLVM.so
Configuring Mesa to build on Fedora 20 with the shared libLLVM.so is ignoring the new --enable-llvm-shared-libs option. It looks like two references to "with_llvm_shared_libs" were missed in configure.ac.
I have attached a patch.
I have a similar patch  which also clears up the remaining messages. It's queued up and I'm planning to commit it shortly. Thanks for the heads up.
I've been having lots of trouble building Mesa for RadeonSI with recent LLVM 3.5 snapshots. I am happy to report that applying Emil's patch from comment 1, in combination with attachment 95368 [details] (from bug 75919), gets everything working for me again. (Without 95368, I get static linkage to LLVM instead of shared, which is comical since my build errors out unless I use the "--enable-llvm-shared-libs" config option.)
Just committed the patch to master, so one should be able to enable/disable the option on demand.
AFAICS one could do some clean-up wrt LLVM handling in configure.ac although I'd rather leave that to someone more experienced in that area.
Emil's patch (now applied in Mesa 9.2.0-devel), along with an LLVM 3.5 build with the proper symlinks (bug 75919), nearly allows me to build Mesa for RadeonSI. In my scrambling about to get the build working again, I forgot that I also had to apply a patch from bug 70410 to get the build working.
Anyway, glad to see this bug closed.