ia32: Only pass the node, not the register, to x87_push().
ia32: Only pass the node, not the register, to x87_set_st().
ia32: Pass the node, not the register index, to x87_on_stack().
ia32: Pass the node, not the register index, to is_fp_live().
ia32: Add and use the helper function move_to_tos().
ia32: Rewrite sim_binop() and sim_Fucom().
ia32: Support "t" and "u" asm constraints in the x87 simulator.