[CompilerType] Simplify the interface a bit more..

Summary:
.. removing IsMeaninglessWithoutTypeResolution(). I'm fairly
confident this was introduced to support swift, where
static types [without dynamic counterpart] don't carry a lot
of value. Since then, the formatters and dynamic type resolution
has been rewritten, and we employ different solutions. This function
is unused here too, so let's get read of it.

<rdar://problem/36377967>

Reviewers: shafik, JDevlieghere, alex, compnerd, teemperor

Subscribers: lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D65782

llvm-svn: 367957