librustc_back: expose all target options via JSON
librustc_back: expose all target options via JSON

Not all TargetOptions are exposed via the JSON interface to create
different targets. This exposes all the missing items and reorders them
to match the structure so that it is easier in the future to identify
missing items.

Signed-off-by: Doug Goldstein <8172f793ca553050868d487fd13b508d19cae503@cardoe.com>

graydon/rust,GBGamer/rust,GBGamer/rust,GBGamer/rust,aidancully/rust,aidancully/rust,graydon/rust,GBGamer/rust,graydon/rust,aidancully/rust,graydon/rust,GBGamer/rust,GBGamer/rust,GBGamer/rust,aidancully/rust,aidancully/rust,GBGamer/rust,graydon/rust,graydon/rust,aidancully/rust