Add test.

Author: tianqingw

clang/test/CodeGenSYCL/kernel-early-optimization-pipeline.cpp

@@ -0,0 +1,10 @@
+// Check LLVM optimization pipeline is run by default for SPIR-V compiled for
+// SYCL device target, and can be disabled with -fno-sycl-early-optimizations.
+//
+// RUN: %clang_cc1 -O2 -fsycl -fsycl-is-device -triple spir64-unknown-unknown-sycldevice %s -mllvm -debug-pass=Structure -emit-llvm -o - 2>&1 | FileCheck %s --check-prefix=CHECK-EARLYOPT
+// CHECK-EARLYOPT: Lower Work Group Scope Code
+// CHECK-EARLYOPT: Combine redundant instructions
+//
+// RUN: %clang_cc1 -O2 -fsycl -fsycl-is-device -fno-sycl-early-optimizations -triple spir64-unknown-unknown-sycldevice %s -mllvm -debug-pass=Structure -emit-llvm -o - 2>&1 | FileCheck %s --check-prefix=CHECK-NOEARLYOPT
+// CHECK-NOEARLYOPT: Lower Work Group Scope Code
+// CHECK-NOEARLYOPT-NOT: Combine redundant instructions