PR #1915: Fix SYCL Build Compatibility with Intel LLVM Compiler on Windows for abseil

Imported from GitHub PR #1915

Add platform-specific thread-local storage definition for Intel's LLVM compiler when building with SYCL. The Intel LLVM compiler (icx) with  SYCL enabled requires GCC-style thread-local storage (__thread) rather  than Windows-specific __declspec(thread) when compiling for SYCL device code.

This resolves the build error: "thread-local storage is not supported for  the current target" when building with Intel oneAPI env on Windows systems.

Merge 2596bc8 into e5266cd

Merging this change closes #1915

COPYBARA_INTEGRATE_REVIEW=#1915 from ContradNamiseb:patch-1 2596bc8
PiperOrigin-RevId: 792213053
Change-Id: Ib53808f0c604749e00ae3da4c9070ab21e19c8d4

Author: ContradNamiseb

absl/base/config.h

@@ -237,6 +237,8 @@ static_assert(ABSL_INTERNAL_INLINE_NAMESPACE_STR[0] != 'h' ||
 #error ABSL_HAVE_TLS cannot be directly set
 #elif (defined(__linux__)) && (defined(__clang__) || defined(_GLIBCXX_HAVE_TLS))
 #define ABSL_HAVE_TLS 1
+#elif defined(__INTEL_LLVM_COMPILER)
+#define ABSL_HAVE_TLS 1
 #endif
 
 // ABSL_HAVE_STD_IS_TRIVIALLY_DESTRUCTIBLE