Parsing instruments and analysis regions causes us to see the same
labels two times since we parse the same file twice under the same
context.
This change creates a seperate context for instrument parsing
and another for analysis region parsing. I will post a follow up
commit once I get some free cycles to parse analysis regions and
instruments in one parsing pass under a single context.
Differential Revision: https://reviews.llvm.org/D149781
1c2b8129e9