[llvm] [libsycl] Add lit configuration files and basic test (PR #177407)

[Kseniya Tikhomirova via llvm-commits]

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@@ -0,0 +1,36 @@
+cmake_minimum_required(VERSION 3.20.0)
+
+message("Configuring SYCL End-to-End Tests")
+
+set(LIBSYCL_CXX_COMPILER "${LLVM_BINARY_DIR}/bin/clang++")
+set(LIBSYCL_E2E_CXX_FLAGS "" CACHE STRING
+    "Flags passed to clang++ when building SYCL end-to-end tests")
+
+if(NOT LIBSYCL_TEST_E2E_TARGETS)
+  set(LIBSYCL_TEST_E2E_TARGETS "all")
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KseniyaTikhomirova wrote:

removed this for now, will add back once we have more options.

https://github.com/llvm/llvm-project/pull/177407