PR target/86984
* expr.c (expand_assignment): Assert that bitpos is positive.
(store_field): Likewise
(expand_expr_real_1): Make sure that bitpos is positive.
* config/alpha/alpha.h (CONSTANT_ADDRESS_P): Avoid signed
integer overflow.
PR target/86984
* gcc.target/alpha/pr86984.c: New test.
From-SVN: r263664
