For PR777:

Add an additional catch block to ensure that this function can't throw any
exceptions, even one's we're not expecting.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@28309 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Support/FileUtilities.cpp

@@ -241,5 +241,8 @@ int llvm::DiffFilesWithTolerance(const sys::Path &FileA,
   } catch (const std::string &Msg) {
     if (Error) *Error = Msg;
     return 2;
+  } catch (...) {
+    *Error = "Unknown Exception Occurred";
+    return 2;
   }
 }