[llvm] [llvm][support] Show name of overlapping cl option (PR #70108)

[Arthur Eubanks via llvm-commits]

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@@ -863,7 +863,11 @@ template <class DataType> class parser : public generic_parser_base {
   ///
   template <class DT>
   void addLiteralOption(StringRef Name, const DT &V, StringRef HelpStr) {
-    assert(findOption(Name) == Values.size() && "Option already exists!");
+#ifndef NDEBUG
+    if (findOption(Name) != Values.size()) {
+      report_fatal_error("Option " + Name + " already exists!", false);
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aeubanks wrote:

actually we should keep the default `true`

https://github.com/llvm/llvm-project/pull/70108