Assigning and copying command line option objects shouldn't be allowed.

Summary:
The default copy and assignment operators for these objects probably don't actually do what the clients intend, so they should be deleted.

Places using the assignment operator to set the value of an option should cast to the option's data type first to call into the override for operator=. Places using the copy constructor just need to be changed to not copy (i.e. passing by const reference instead of value).

Reviewers: dexonsmith, chandlerc

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D7114

llvm-svn: 226762