- Native linker: some features missing, falling back to external linker

- interchange and extended float types (just aliased, no __STDC_IEC_60559_TYPES__)

- add more cheap -O2 passes, but no need for SSA analysis (yet).
  Like removing the REX prefix, strength reduction, ...

- optional QBE backend for -O2?

- SSA conversion for -O2?
