The TypeRef.OpaqueType() method is currently commented out. Uncommenting it gives the following error:
INFO: Failed to get address of method public static native llvm.binding.LLVMLibrary$LLVMTypeRef llvm.binding.LLVMLibrary.LLVMOpaqueType()
Exception in thread "main" java.lang.UnsatisfiedLinkError: llvm.binding.LLVMLibrary.LLVMOpaqueType()Lllvm/binding/LLVMLibrary$LLVMTypeRef;
at llvm.binding.LLVMLibrary.LLVMOpaqueType(Native Method)
at llvm.TypeRef.OpaqueType(TypeRef.java:112)
Alas, I can not yet propose a solution.