Framework code may call PreparePacckage with NULL GUID and both IFR and String Packages.

PackageList = PreparePackages (2, NULL, IfrPack, StringPack);

    mHii->NewPack( mHii, PackageList, &HiiHandle );

Framework HII database make use of the formset GUID as ID to retrieve String using 

EFI_STATUS
GetStringFromToken (
  IN  EFI_GUID                  *ProducerGuid,
  IN  STRING_REF                Token,
  OUT CHAR16                    **String
  )

Update the code to cache the Formset GUID too.

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@5896 6f19259b-4bc3-4df7-8a09-765794883524

EdkCompatibilityPkg/Compatibility/FrameworkHiiToUefiHiiThunk/Utility.h

@@ -107,4 +107,17 @@ DestoryOneOfOptionMap (
   IN LIST_ENTRY     *OneOfOptionMapListHead
   );
 
+VOID
+GetFormSetGuid (
+  IN  EFI_HII_PACKAGE_HEADER  *Package,
+  OUT EFI_GUID                *FormSetGuid
+  )
+;
+
+EFI_HII_PACKAGE_HEADER *
+GetIfrPackage (
+  IN CONST EFI_HII_PACKAGES               *Packages
+  )
+;
+
 #endif