Move DCE after all SPIRV metadata related passes

`HandleSpirvDecorationMetadata` transforms `spirv.Decorations` metadata
produced by Khronos SPIRV-LLVM Translator into internal IGC's representation.
The metadata can be attached to instructions that may be removed by DCE
pass, hence losing them.

Author: aratajew

IGC/AdaptorOCL/UnifyIROCL.cpp

@@ -325,14 +325,14 @@ static void CommonOCLBasedPasses(
 #endif // IGC_SCALAR_USE_KHRONOS_SPIRV_TRANSLATOR
     mpmSPIR.add(new TypesLegalizationPass());
     mpmSPIR.add(new TargetLibraryInfoWrapperPass());
-    mpmSPIR.add(createDeadCodeEliminationPass());
     mpmSPIR.add(new MetaDataUtilsWrapper(pMdUtils, pContext->getModuleMetaData()));
     mpmSPIR.add(new CodeGenContextWrapper(pContext));
     mpmSPIR.add(new SPIRMetaDataTranslation());
 #ifdef IGC_SCALAR_USE_KHRONOS_SPIRV_TRANSLATOR
     mpmSPIR.add(new ConvertUserSemanticDecoratorOnFunctions());
 #endif // IGC_SCALAR_USE_KHRONOS_SPIRV_TRANSLATOR
     mpmSPIR.add(new HandleSpirvDecorationMetadata());
+    mpmSPIR.add(createDeadCodeEliminationPass());
     mpmSPIR.run(*pContext->getModule());
 
     bool isOptDisabled = CompilerOpts.OptDisable;