[clang] [NFC] Change SYCL test file extension .c -> .cpp (PR #173937)

[via cfe-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang-driver

Author: Alexey Bader (bader)

<details>
<summary>Changes</summary>

SYCL is an API built on top of C++ programming language. Building SYCL
program with C compiler is not possible.

---
Full diff: https://github.com/llvm/llvm-project/pull/173937.diff


1 Files Affected:

- (renamed) clang/test/Driver/sycl.cpp () 


``````````diff
diff --git a/clang/test/Driver/sycl.c b/clang/test/Driver/sycl.cpp
similarity index 100%
rename from clang/test/Driver/sycl.c
rename to clang/test/Driver/sycl.cpp

``````````

</details>


https://github.com/llvm/llvm-project/pull/173937