[NFC] Fix "unused parameter" error revealed in the Linux self-build.

[aaron.ballman]

LGTM! The CI build failures look to be entirely unrelated to any changes in this patch, but please keep an eye on the build bots once you land this just in case there's a real issue.

[zahiraam]

In D98632#2626334, @aaron.ballman wrote:

LGTM! The CI build failures look to be entirely unrelated to any changes in this patch, but please keep an eye on the build bots once you land this just in case there's a real issue.

Thanks Aaron. Yes will do that.

llvm/include/llvm/ADT/IntrusiveRefCntPtr.h

 }
 
 template <class T, class U>
 inline bool operator!=(T *A, const IntrusiveRefCntPtr<U> &B) {
   return A != B.get();
 }
 
 template <class T>
-bool operator==(std::nullptr_t A, const IntrusiveRefCntPtr<T> &B) {
+bool operator==(std::nullptr_t, const IntrusiveRefCntPtr<T> &B) {
   return !B;
 }
 
 template <class T>
 bool operator==(const IntrusiveRefCntPtr<T> &A, std::nullptr_t B) {
   return B == A;
 }
 

llvm/include/llvm/Support/Error.h

 
 private:
   template <class T1>
   static bool compareThisIfSameType(const T1 &a, const T1 &b) {
     return &a == &b;
   }
 
   template <class T1, class T2>
-  static bool compareThisIfSameType(const T1 &a, const T2 &b) {
+  static bool compareThisIfSameType(const T1 &, const T2 &) {
     return false;
   }
 
   template <class OtherT> void moveConstruct(Expected<OtherT> &&Other) {
     HasError = Other.HasError;
 #if LLVM_ENABLE_ABI_BREAKING_CHECKS
     Unchecked = true;
     Other.Unchecked = false;

llvm/include/llvm/Support/FormatVariadicDetails.h

 template <typename T>
 class stream_operator_format_adapter : public format_adapter {
   T Item;
 
 public:
   explicit stream_operator_format_adapter(T &&Item)
       : Item(std::forward<T>(Item)) {}
 
-  void format(llvm::raw_ostream &S, StringRef Options) override { S << Item; }
+  void format(llvm::raw_ostream &S, StringRef) override { S << Item; }
 };
 
 template <typename T> class missing_format_adapter;
 
 // Test if format_provider<T> is defined on T and contains a member function
 // with the signature:
 //   static void format(const T&, raw_stream &, StringRef);
 //
build_format_adapter(T &&Item) {
   static_assert(
       !std::is_same<llvm::Error, std::remove_cv_t<T>>::value,
       "llvm::Error-by-value must be wrapped in fmt_consume() for formatv");
   return stream_operator_format_adapter<T>(std::forward<T>(Item));
 }
 
 template <typename T>
 std::enable_if_t<uses_missing_provider<T>::value, missing_format_adapter<T>>
-build_format_adapter(T &&Item) {
+build_format_adapter(T &&) {
   return missing_format_adapter<T>();
 }
 }
 }
 
 #endif