[Support] Fix ErrorOr assertion when /proc/cpuinfo doesn't exist.

The ErrorOr should not be dereferenced on the error path.

Patch by Jacob Young

Reviewers: tejohnson

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D32032

llvm-svn: 300267

llvm/lib/Support/Host.cpp

@@ -1245,6 +1245,7 @@ static int computeHostNumPhysicalCores() {
   if (std::error_code EC = Text.getError()) {
     llvm::errs() << "Can't read "
                  << "/proc/cpuinfo: " << EC.message() << "\n";
+    return -1;
   }
   SmallVector<StringRef, 8> strs;
   (*Text)->getBuffer().split(strs, "\n", /*MaxSplit=*/-1,