Changes

Recommit r369190 "[llvm-readobj/llvm-readelf] - Improve/cleanup the
error reporting API."
Fix: Add a `consumeError` call removed by mistake to 'printStackSize', 
this should fix the "Expected<T> must be checked before access or
destruction." reported by following bot: 
http://lab.llvm.org:8011/builders/clang-x64-windows-msvc/builds/9743/steps/stage%201%20check/logs/stdio
Original commit message: Currently we have the following functions for
error reporting:
LLVM_ATTRIBUTE_NORETURN void reportError(Twine Msg); void
reportError(Error Err, StringRef Input);  void reportWarning(Twine Msg); 
void reportWarning(StringRef Input, Error Err); void warn(llvm::Error
Err); void error(std::error_code EC);
Problems are: naming is inconsistent, arguments order is inconsistent, 
some of the functions looks excessive.
After applying this patch we have:
void reportError(Error Err, StringRef Input);  void
reportError(std::error_code EC, StringRef Input); void
reportWarning(Error Err, StringRef Input);
I'd be happy to remove reportError(std::error_code EC, StringRef Input)
too, but it is used by COFF heavily.
Test cases were updated, they show an improvement introduced.
Differential revision: https://reviews.llvm.org/D66286
llvm-svn: 369194