[SYCL][NFC] Make the RT::PiPlugin object private

Signed-off-by: Artem Gindinson <artem.gindinson@intel.com>

Author: Artem Gindinson

sycl/source/detail/plugin.hpp

@@ -29,6 +29,8 @@ class plugin {
 
   ~plugin() = default;
 
+  const RT::PiPlugin &getPiPlugin() const { return MPlugin; }
+
   /// Checks return value from PI calls.
   ///
   /// \throw Exception if pi_result is not a PI_SUCCESS.
@@ -71,11 +73,9 @@ class plugin {
     RT::PiResult Err = call_nocheck<PiApiOffset>(Args...);
     checkPiResult(Err);
   }
-  // TODO: Make this private. Currently used in program_manager to create a
-  // pointer to PiProgram.
-  RT::PiPlugin MPlugin;
 
 private:
+  RT::PiPlugin MPlugin;
   bool MPiEnableTrace;
 
 }; // class plugin

sycl/source/detail/program_manager/program_manager.cpp

@@ -367,8 +367,8 @@ ProgramManager::getBuiltPIProgram(OSModuleHandle M, const context &Context,
     ContextImplPtr ContextImpl = getSyclObjImpl(Context);
     const detail::plugin &Plugin = ContextImpl->getPlugin();
     RT::PiProgram Prg = createPIProgram(Img, Context);
-    ProgramPtr ProgramManaged(Prg,
-                              Plugin.MPlugin.PiFunctionTable.piProgramRelease);
+    ProgramPtr ProgramManaged(
+        Prg, Plugin.getPiPlugin().PiFunctionTable.piProgramRelease);
 
     // Link a fallback implementation of device libraries if they are not
     // supported by a device compiler.