Fix build for gcc users by declaring variables for unions in structs which don't declare a variable. The size before/after this change of the structs doesn't change with gcc/clang.
Fix build for gcc users by declaring variables for unions in structs which
don't declare a variable. The size before/after this change of the structs
doesn't change with gcc/clang.

Noticed by:	several
Suggested by:	Gary Jennejohn <gljennjohn@googlemail.com>

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