* i386.c (i386_preferred_stack_boundary_string): New global variable.
        (i386_preferred_stack_boundary): New global variable.
        (override_functions): Set it.  Tidy option setting code.
        * i386.h (TARGET_OPTIONS): New command line option.
        (i386_preferred_stack_boundary_string): Declare it.
        (i386_preferred_stack_boundary): Likewise.
        (PREFERRED_STACK_BOUNDARY): Use i386_preferred_stack_boundary.

From-SVN: r26527