[clangd] Remove unused+broken InvalidationError class.

clang-tools-extra/clangd/TUScheduler.cpp

@@ -1093,15 +1093,5 @@ DebouncePolicy DebouncePolicy::fixed(clock::duration T) {
   return P;
 }
 
-void TUScheduler::InvalidatedError::log(llvm::raw_ostream &OS) const {
-  switch (Policy) {
-  case InvalidateOnUpdate:
-    OS << "Task was cancelled due to a subsequent change to the file.";
-    break;
-  case NoInvalidation:
-    llvm_unreachable("Invalidated for no reason?");
-  }
-}
-
 } // namespace clangd
 } // namespace clang

clang-tools-extra/clangd/TUScheduler.h

@@ -230,27 +230,14 @@ class TUScheduler {
     InvalidateOnUpdate,
   };
 
-  /// Error to return when an ASTActionInvalidation policy fires.
-  class InvalidatedError : public llvm::ErrorInfo<InvalidatedError> {
-  public:
-    static char ID;
-    ASTActionInvalidation Policy;
-
-    void log(llvm::raw_ostream &OS) const override;
-    std::error_code convertToErrorCode() const override {
-      return std::make_error_code(std::errc::interrupted);
-    }
-  };
-
   /// Schedule an async read of the AST. \p Action will be called when AST is
   /// ready. The AST passed to \p Action refers to the version of \p File
   /// tracked at the time of the call, even if new updates are received before
   /// \p Action is executed.
   /// If an error occurs during processing, it is forwarded to the \p Action
   /// callback.
-  /// If the context is cancelled before the AST is ready, the callback will
-  /// receive a CancelledError. If the invalidation policy is triggered, the
-  /// callback will receive an InvalidatedError.
+  /// If the context is cancelled before the AST is ready, or the invalidation
+  /// policy is triggered, the callback will receive a CancelledError.
   void runWithAST(llvm::StringRef Name, PathRef File,
                   Callback<InputsAndAST> Action,
                   ASTActionInvalidation = NoInvalidation);