Audited the existing Materializer code to ensure
that it works in the absence of a process.  Codepaths
in the Materializer now use the best execution context
scope available to them.


git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@179539 91177308-0d34-0410-b5e6-96231b3b80d8