[clang] [Clang][OpenCL] Add OpenCL 3.1 language version (PR #204043)

[Wenju He via cfe-commits]

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@@ -153,6 +153,8 @@ void LangOptions::setLangDefaults(LangOptions &Opts, Language Lang,
     Opts.OpenCLVersion = 200;
   else if (LangStd == LangStandard::lang_opencl30)
     Opts.OpenCLVersion = 300;
+  else if (LangStd == LangStandard::lang_opencl31)
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wenju-he wrote:

> A separate refactoring really ought to replace this with a switch

sure, will follow up, thanks.

https://github.com/llvm/llvm-project/pull/204043