Set gold plugin options in a sane order.

This fixes the  processing of --plugin-opt=-jump-table-type=arity.

Nice properties:
 * We call InitTargetOptionsFromCodeGenFlags once.
 * We call parseCodeGenDebugOptions once.
 * It works :-)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211322 91177308-0d34-0410-b5e6-96231b3b80d8