[clang] [Driver][SYCL] Error on C inputs when compiling with -fsycl (PR #200318)

[Aaron Ballman via cfe-commits]

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@@ -3227,7 +3228,8 @@ void Driver::BuildInputs(const ToolChain &TC, DerivedArgList &Args,
       if (DiagnoseInputExistence(Value, types::TY_C,
                                  /*TypoCorrect=*/false)) {
         Arg *InputArg = makeInputArg(Args, Opts, A->getValue());
-        Inputs.push_back(std::make_pair(types::TY_C, InputArg));
+        Inputs.push_back(
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AaronBallman wrote:

I'd like to see a clang-cl test case which passes `/TC` because this seems incorrect to me; won't this quietly switch the file type to C++ in `-fsycl` mode?

https://github.com/llvm/llvm-project/pull/200318