Retry "[ProfileData] (llvm) Use Error in InstrProf and Coverage, NFC"
Transition InstrProf and Coverage over to the stricter Error/Expected
interface.
Changes since the initial commit:
- Fix error message printing in llvm-profdata.
- Check errors in loadTestingFormat() + annotateAllFunctions().
- Defer error handling in InstrProfIterator to InstrProfReader.
Differential Revision: http://reviews.llvm.org/D19901
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@269491
91177308-0d34-0410-b5e6-
96231b3b80d8