[Bug middle-end/88739] Big-endian union bug

[rearnsha at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88739

--- Comment #2 from Richard Earnshaw <rearnsha at gcc dot gnu.org> ---
>   _23 = BIT_FIELD_REF <_2, 16, 0>;            // WRONG: should be _2, 14, 0

_2 is declared as a 30-bit integer, so perhaps the statement is right, but
expand needs to understand that the shift extract of the top 16 bits comes from
a different location in big-endian.