[clang] [llvm] [SystemZ][z/OS] Update autoconversion functions to improve support for UTF-8 (PR #98652)

[Sean Perry via cfe-commits]

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@@ -617,6 +625,23 @@ FileID SourceManager::createFileIDImpl(ContentCache &File, StringRef Filename,
     return FileID::get(LoadedID);
   }
   unsigned FileSize = File.getSize();
+#ifdef __MVS__
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perry-ca wrote:

I think we can just remove #if and make a version of `needzOSConversion` that is not z/OS specific.  

We need to be doing something with the error condition.

https://github.com/llvm/llvm-project/pull/98652