test-spawn failed to build on linux
test-spawn failed to build on linux

- added missing header file
- converted c++ style comment to c style comment

urbit/archaeology2,urbit/archaeology2,urbit/archaeology2,unknownbrackets/maxcso,unknownbrackets/maxcso,urbit/archaeology2,urbit/archaeology2,unknownbrackets/maxcso,unknownbrackets/maxcso,urbit/archaeology2,urbit/archaeology2,urbit/archaeology2,unknownbrackets/maxcso,urbit/archaeology2,unknownbrackets/maxcso,unknownbrackets/maxcso