Move Timer and TraceOptions from Core to Utility

Summary:
The classes have no dependencies, and they are used both by lldb and
lldb-server, so it makes sense for them to live in the lowest layers.

Reviewers: zturner, jingham

Subscribers: emaste, mgorny, lldb-commits

Differential Revision: https://reviews.llvm.org/D34746

llvm-svn: 306682