* config/tc-z80.h(md_register_arithmetic): Define as 0.
* config/tc-z80.c(md_begin): Store register names in symbol table, prevents usage as ordinary symbol.
* config/tc-z80.c(contains_register): New function.
* config/tc-z80.c(parse_exp2): Removed.
* config/tc-z80.c(parse_exp_not_indexed): New function.
* config/tc-z80.c(parse_exp): Add code to recogize indexed addressing after parsing.
* config/tc-z80.c(emit_byte, emit_word): Use contains_register.
* config/tc-z80.c(emit_jp): Use parse_exp_not_indexed, simplify condition for jump to register.
* config/tc-z80.c(emit_call, emit_jr, emit_ex, emit_rst): Use parse_exp_not_indexed.