[clang] [LinkerWrapper] Try to fix testing on Windows (PR #130285)

[Joseph Huber via cfe-commits]

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@@ -599,9 +599,11 @@ Expected<StringRef> writeOffloadFile(const OffloadFile &File) {
 
   StringRef Prefix =
       sys::path::stem(Binary.getMemoryBufferRef().getBufferIdentifier());
-
-  auto TempFileOrErr = createOutputFile(
-      Prefix + "-" + Binary.getTriple() + "-" + Binary.getArch(), "o");
+  SmallString<128> Filename;
+  (Prefix + "-" + Binary.getTriple() + "-" + Binary.getArch())
+      .toNullTerminatedStringRef(Filename);
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jhuber6 wrote:

I think this *technically* works, but you're right that `toVector` is better.

https://github.com/llvm/llvm-project/pull/130285