Remove unnecessary MD for poisoned kernels

After fp64 poisoning, unnecessary MDs exists in the Module.
This change adds `PurgeMetaDataUtils` pass when fp64 poisoning is used.

(cherry picked from commit 2422fe2)

Author: matborzyszkowski

Diff for: IGC/AdaptorOCL/UnifyIROCL.cpp

@@ -579,6 +579,7 @@ static void CommonOCLBasedPasses(
     mpm.add(new ErrorCheck());
     if (pContext->m_Options.EnableUnsupportedFP64Poisoning) {
         mpm.add(new PoisonFP64Kernels());
+        mpm.add(new PurgeMetaDataUtils());
     }
 
     mpm.add(new ImageFuncResolution());