1. Added a set of public interfaces in InstrProfRecord
class to access (read/write) value profile data.
2. Changed IndexedProfile reader and writer code to
use the newly defined interfaces and hide implementation
details.
3. Added a couple of unittests for value profiling:
- Test new interfaces to get and set value profile data
- Test value profile data merging with various scenarios.
No functional change is expected. The new interfaces will also
make it possible to change on-disk format of value prof data
to be more compact (to be submitted).
llvm-svn: 251771