Fix not adding the "include" directory to the spcomp search path.

The OSX binreloc change accidentally dropped an #endif that had the result of entirely disabling the code that adds the "include" directory that's relative to spcomp to the search path list. There was also an extra #endif at the end of the block that was accidentally left in that allowed that to compile.

I also added some spacing and comments to make the preprocessor soup a little more followable.