Do not instrument libFuzzer itself when built with -DLLVM_USE_SANITIZE_COVERAGE
Do not instrument libFuzzer itself when built with -DLLVM_USE_SANITIZE_COVERAGE

Fixes regression from https://reviews.llvm.org/D36295

Differential Revision: https://reviews.llvm.org/D36428

git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@310305 91177308-0d34-0410-b5e6-96231b3b80d8

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