[Autobackout][FunctionalRegression]Revert of change: 8e50c90: Enable vector8 load/store by default.

Enable vector8 load/store by default to all platforms supporting this feature on OCL path.

(cherry picked from commit d1258d4)

Author: sys-igc

IGC/Compiler/CISACodeGen/ShaderCodeGen.cpp

@@ -768,7 +768,7 @@ void AddLegalizationPasses(CodeGenContext& ctx, IGCPassManager& mpm, PSSignature
         bool AllowVector8LoadStore =
             IGC_IS_FLAG_ENABLED(EnableVector8LoadStore) ||
             ((ctx.type == ShaderType::RAYTRACING_SHADER || ctx.hasSyncRTCalls()) && ctx.platform.supports8DWLSCMessage()) ||
-            (ctx.platform.isCoreChildOf(IGFX_XE_HPC_CORE) && ctx.platform.supports8DWLSCMessage());
+            ctx.platform.getPlatformInfo().eProductFamily == IGFX_PVC;
 
         mpm.add(createMemOptPass(AllowNegativeSymPtrsForLoad, AllowVector8LoadStore));