Index: lld/Common/ErrorHandler.cpp
===================================================================
--- lld/Common/ErrorHandler.cpp
+++ lld/Common/ErrorHandler.cpp
@@ -48,7 +48,8 @@
 
 void lld::exitLld(int Val) {
   // Delete the output buffer so that any tempory file is deleted.
-  errorHandler().OutputBuffer.reset();
+  if (errorHandler().OutputBuffer)
+    errorHandler().OutputBuffer->discard();
 
   // Dealloc/destroy ManagedStatic variables before calling
   // _exit(). In a non-LTO build, this is a nop. In an LTO
Index: llvm/include/llvm/Support/FileOutputBuffer.h
===================================================================
--- llvm/include/llvm/Support/FileOutputBuffer.h
+++ llvm/include/llvm/Support/FileOutputBuffer.h
@@ -76,6 +76,10 @@
   /// deallocates the buffer and the target file is never written.
   virtual ~FileOutputBuffer() {}
 
+  /// This removes the temporary file (unless it already was committed)
+  /// but keeps the memory mapping alive.
+  virtual void discard() {}
+
 protected:
   FileOutputBuffer(StringRef Path) : FinalPath(Path) {}
 
Index: llvm/lib/Support/FileOutputBuffer.cpp
===================================================================
--- llvm/lib/Support/FileOutputBuffer.cpp
+++ llvm/lib/Support/FileOutputBuffer.cpp
@@ -61,6 +61,13 @@
     consumeError(Temp.discard());
   }
 
+  void discard() override {
+    // Delete the temp file if it still was open, but keeping the mapping
+    // active. (Closing the FD while keeping the mapping alive seems to work
+    // on windows as well.)
+    consumeError(Temp.discard());
+  }
+
 private:
   std::unique_ptr<fs::mapped_file_region> Buffer;
   fs::TempFile Temp;