Use an enum class.

Might also fix the windows build.

llvm-svn: 210077
diff --git a/llvm/lib/ProfileData/InstrProf.cpp b/llvm/lib/ProfileData/InstrProf.cpp
index 60a8efb..a658313 100644
--- a/llvm/lib/ProfileData/InstrProf.cpp
+++ b/llvm/lib/ProfileData/InstrProf.cpp
@@ -21,7 +21,7 @@
 class InstrProfErrorCategoryType : public error_category {
   const char *name() const override { return "llvm.instrprof"; }
   std::string message(int IE) const override {
-    instrprof_error::ErrorType E = static_cast<instrprof_error::ErrorType>(IE);
+    instrprof_error E = static_cast<instrprof_error>(IE);
     switch (E) {
     case instrprof_error::success:
       return "Success";
@@ -53,7 +53,7 @@
     llvm_unreachable("A value of instrprof_error has no message.");
   }
   error_condition default_error_condition(int EV) const override {
-    if (EV == instrprof_error::success)
+    if (static_cast<instrprof_error>(EV) == instrprof_error::success)
       return error_condition();
     return errc::invalid_argument;
   }