/usr/lib/ocaml/llvm-3.1/libLLVMX86AsmPrinter.a is in libllvm-3.1-ocaml-dev 3.1-2ubuntu1~12.04.1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/ocaml/llvm-3.1/../../llvm-3.1/lib/libLLVMX86AsmPrinter.a