[NFCI][SYCL] Minor code cleanup (#17647)

Author: aelovikov-intel

sycl/include/sycl/detail/cg_types.hpp

@@ -164,11 +164,7 @@ class HostKernelBase {
 // Class which stores specific lambda object.
 template <class KernelType, class KernelArgType, int Dims>
 class HostKernel : public HostKernelBase {
-  using IDBuilder = sycl::detail::Builder;
   KernelType MKernel;
-  // Allowing accessing MKernel from 'ResetHostKernelHelper' method of
-  // 'sycl::handler'
-  friend class sycl::handler;
 
 public:
   HostKernel(KernelType Kernel) : MKernel(Kernel) {}
@@ -182,6 +178,7 @@ class HostKernel : public HostKernelBase {
   // kernel code instructions with source code lines.
   // NOTE: InstatiateKernelOnHost() should not be called.
   void InstantiateKernelOnHost() override {
+    using IDBuilder = sycl::detail::Builder;
     if constexpr (std::is_same_v<KernelArgType, void>) {
       runKernelWithoutArg(MKernel);
     } else if constexpr (std::is_same_v<KernelArgType, sycl::id<Dims>>) {

sycl/include/sycl/handler.hpp

@@ -753,7 +753,7 @@ class __SYCL_EXPORT handler {
 #endif
     // Empty name indicates that the compilation happens without integration
     // header, so don't perform things that require it.
-    if (KernelHasName) {
+    if constexpr (KernelHasName) {
       // TODO support ESIMD in no-integration-header case too.
       clearArgs();
       extractArgsAndReqsFromLambda(MHostKernel->getPtr(),
@@ -770,7 +770,7 @@ class __SYCL_EXPORT handler {
 
     // If the kernel lambda is callable with a kernel_handler argument, manifest
     // the associated kernel handler.
-    if (IsCallableWithKernelHandler) {
+    if constexpr (IsCallableWithKernelHandler) {
       getOrInsertHandlerKernelBundle(/*Insert=*/true);
     }
   }