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

llvm-svn: 269491

llvm/tools/llvm-cov/CodeCoverage.cpp

@@ -210,10 +210,9 @@ std::unique_ptr<CoverageMapping> CodeCoverageTool::load() {
     errs() << "warning: profile data may be out of date - object is newer\n";
   auto CoverageOrErr = CoverageMapping::load(ObjectFilename, PGOFilename,
                                              CoverageArch);
-  if (std::error_code EC = CoverageOrErr.getError()) {
+  if (Error E = CoverageOrErr.takeError()) {
     colored_ostream(errs(), raw_ostream::RED)
-        << "error: Failed to load coverage: " << EC.message();
-    errs() << "\n";
+        << "error: Failed to load coverage: " << toString(std::move(E)) << "\n";
     return nullptr;
   }
   auto Coverage = std::move(CoverageOrErr.get());