Turn cl::values() (for enum) from a vararg function to using C++ variadic template

The core of the change is supposed to be NFC, however it also fixes
what I believe was an undefined behavior when calling:

 va_start(ValueArgs, Desc);

with Desc being a StringRef.

Differential Revision: https://reviews.llvm.org/D25342

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@283671 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Analysis/BlockFrequencyInfo.cpp

@@ -39,8 +39,7 @@ static cl::opt<GVDAGType> ViewBlockFreqPropagationDAG(
                           "display a graph using the raw "
                           "integer fractional block frequency representation."),
                clEnumValN(GVDT_Count, "count", "display a graph using the real "
-                                               "profile count if available."),
-               clEnumValEnd));
+                                               "profile count if available.")));
 
 cl::opt<std::string>
     ViewBlockFreqFuncName("view-bfi-func-name", cl::Hidden,