[SPARC] Remove dead code

Remove dead/unused/non-implemented code:
InterpreterMacroAssembler::verify_FPU
MacroAssembler::iprefetch
MacroAssembler::push_fTOS
MacroAssembler::pop_fTOS
MacroAssembler::empty_FPU_stack
MacroAssembler::push_IU_state
MacroAssembler::pop_IU_state
MacroAssembler::push_FPU_state
MacroAssembler::pop_FPU_state
MacroAssembler::push_CPU_state
MacroAssembler::pop_CPU_state
MacroAssembler::verify_FPU
MacroAssembler::print_CPU_state