Make sure that the go bindings call LLVMInitializeMCJITCompilerOptions
so that they initialize the code generation model to the correct
(non-zero) default model.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222804 91177308-0d34-0410-b5e6-96231b3b80d8
Make SetMCJITOptimizationLevel more of a method and pass options
as a reference. Move closer to the type.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222805 91177308-0d34-0410-b5e6-96231b3b80d8
Reformat with gofmt.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222806 91177308-0d34-0410-b5e6-96231b3b80d8