 [llvm-mca] Add an error handler for error from parseCodeRegions
 [llvm-mca] Add an error handler for error from parseCodeRegions

Summary:
It's a bit tricky to add a test for the failing path right now, binary support will have an easier path to exercise the path here.

* Ran clang-format.



Reviewers: andreadb

Reviewed By: andreadb

Subscribers: tschuett, gbedwell, llvm-commits

Differential Revision: https://reviews.llvm.org/D55803

git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@349659 91177308-0d34-0410-b5e6-96231b3b80d8

apple/swift-llvm,llvm-mirror/llvm,GPUOpen-Drivers/llvm,apple/swift-llvm,GPUOpen-Drivers/llvm,apple/swift-llvm,apple/swift-llvm,llvm-mirror/llvm,apple/swift-llvm,apple/swift-llvm,GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm,llvm-mirror/llvm,llvm-mirror/llvm,GPUOpen-Drivers/llvm,llvm-mirror/llvm,llvm-mirror/llvm,GPUOpen-Drivers/llvm,llvm-mirror/llvm,GPUOpen-Drivers/llvm,llvm-mirror/llvm,apple/swift-llvm,apple/swift-llvm,llvm-mirror/llvm