PR middle-end/14289
* c-typeck.c (c_mark_addressable): A register variable should
be considered global if its not automatic, i.e. TREE_PUBLIC,
TREE_STATIC or DECL_EXTERNAL.
* function.c (put_var_into_stack): Call abort when placing a
hard register into the stack, if x_parm_reg_stack_loc is NULL.
* gcc.dg/pr14289-1.c: New test case.
* gcc.dg/pr14289-2.c: Likewise.
* gcc.dg/pr14289-3.c: Likewise.