If someone adds x86 site macros in the ix86-common file, it can break the x32 build. This is not a issue when the x86 macro is also not defined, because in that case compiler should give the right value. find out all the basic macros which will be different for x32 from x86, and add them to the x32 site file. Also mention in the x86-common site file that this file is also used for the x32 targets.
As an extension to this we can hopefully consolidate many of the feature checks which are really linux features and not machine-specific to a general linux site file.
No more x32 site file fixes are identified.