Drop SrcStructTypesSet. It is redundant.
Drop SrcStructTypesSet. It is redundant.

At the only point in the code it is used, we haven't added any of the src types
to DstStructTypesSet yet.

git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@223057 91177308-0d34-0410-b5e6-96231b3b80d8

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