This checkin introduces the notion of hardcoded formatters, which LLDB can bind to a ValueObject internally depending on any criteria
User-vended by-type formatters still would prevail on these hardcoded ones

For the time being, while the infrastructure is there, no such formatters exist

This can be useful for cases such as expanding vtables for C++ class pointers, when there is no clear cut notion of a typename matching, and the feature is low-level enough that it makes sense for the debugger core to be vending it

git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@193724 91177308-0d34-0410-b5e6-96231b3b80d8