update per review comments

Author: wenju-he

clang/lib/Driver/ToolChains/SYCL.cpp

@@ -64,19 +64,10 @@ const char *SYCLInstallationDetector::findLibspirvPath(
 
   const SmallString<64> Basename =
       getLibSpirvBasename(DeviceTriple, HostTriple);
-  auto searchAt = [&](StringRef Path, const Twine &a = "", const Twine &b = "",
-                      const Twine &c = "") -> const char * {
-    SmallString<128> LibraryPath(Path);
-    llvm::sys::path::append(LibraryPath, a, b, c, Basename);
-
-    if (D.getVFS().exists(LibraryPath))
-      return Args.MakeArgString(LibraryPath);
-
-    return nullptr;
-  };
-
-  if (const char *R = searchAt(D.ResourceDir, "lib", "libclc"))
-    return R;
+  SmallString<256> LibclcPath(D.ResourceDir);
+  llvm::sys::path::append(LibclcPath, "lib", "libclc", Basename);
+  if (D.getVFS().exists(LibclcPath))
+    return Args.MakeArgString(LibclcPath);
 
   return nullptr;
 }

clang/test/Driver/Inputs/SYCL/bin/.gitkeep

@@ -3,10 +3,10 @@
 // DEFINE: %{resource_dir} = %/S/Inputs/SYCL/lib/clang/resource_dir
 
 // RUN: %clang -### -resource-dir %{resource_dir} -fsycl -fsycl-targets=nvptx64-nvidia-cuda -nocudalib -target x86_64-unknown-windows-msvc %s 2>&1 \
-// RUN: | FileCheck %s -DRESOURCE_DIR=%{resource_dir} --check-prefixes=CHECK-WINDOWS
+// RUN: | FileCheck %s --check-prefixes=CHECK-WINDOWS
 // RUN: %clang -### -resource-dir %{resource_dir} -fsycl -fsycl-targets=nvptx64-nvidia-cuda -nocudalib -target x86_64-unknown-windows-gnu %s 2>&1 \
-// RUN: | FileCheck %s -DRESOURCE_DIR=%{resource_dir} --check-prefixes=CHECK-WINDOWS
-// CHECK-WINDOWS: "-cc1"{{.*}} "-fsycl-is-device"{{.*}} "-mlink-builtin-bitcode" "[[RESOURCE_DIR]]{{.*[\\/]}}remangled-l32-signed_char.libspirv-nvptx64-nvidia-cuda.bc"
+// RUN: | FileCheck %s --check-prefixes=CHECK-WINDOWS
+// CHECK-WINDOWS: "-cc1"{{.*}} "-fsycl-is-device"{{.*}} "-mlink-builtin-bitcode" "{{.*[\\/]}}remangled-l32-signed_char.libspirv-nvptx64-nvidia-cuda.bc"
 //
 // RUN: %clang -### -resource-dir %{resource_dir} -fsycl -fsycl-targets=nvptx64-nvidia-cuda -nocudalib -target x86_64-unknown-linux-gnu %s 2>&1 \
 // RUN: | FileCheck %s -DRESOURCE_DIR=%{resource_dir} --check-prefixes=CHECK-LINUX