Use flavors for postgresql-server
Could you use devel/arcanist, or at least generate a diff with full context like it does, with svn diff -x -U9999 or git diff -U9999.
Also, could you please remove all whitespace only changes.
Wrong place in the Makefile. See Chapter 15. Order of Variables in Port Makefiles.
Also, as you set FLAVOR?=, you can remove the :U in the .if.
Also, move the *_PKGNAMESUFFIX out of the .if.
This should probably be using LLVM_DEFAULT instead of creating a new LLVM_VERSION.