This provides a library to work with the instrumentation based
profiling format that is used by clang's -fprofile-instr-* options and
by the llvm-profdata tool. This is a binary format, rather than the
textual one that's currently in use.
The tests are in the subsequent commits that use this.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203703 91177308-0d34-0410-b5e6-96231b3b80d8
