[lldb] Get the TargetAPI lock in SBProcess::IsInstrumentationRuntimePresent

Summary:
We should get the TargetAPI lock here to prevent the process of being destroyed while we are in the function. Thanks Jim for explaining what's going on.

Fixes rdar://54424754

Reviewers: jingham

Reviewed By: jingham

Subscribers: JDevlieghere, lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D67831

llvm-svn: 373725