Driver support for -fdebug-types-sections

Using backend-option like a few other debug codegen flags. I believe
Eric Christopher's working at porting those over to something nicer
such as an API level CodeGenOptions or the like, so this can be
improved along with that work.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@199535 91177308-0d34-0410-b5e6-96231b3b80d8