Fix: Struct field parameters were unnecessarily generating "init ops" to set their default values, rather than relying on the constant initializer values like simple types.
Fix: Struct field parameters were unnecessarily generating "init ops" to
set their default values, rather than relying on the constant
initializer values like simple types.

Review by: ckulla
http://codereview.appspot.com/218058/show


h3rb/openshadinglanguage,h3rb/openshadinglanguage,tectronics/openshadinglanguage,qdtk/openshadinglanguage,tectronics/openshadinglanguage,h3rb/openshadinglanguage,h3rb/openshadinglanguage,qdtk/openshadinglanguage,tectronics/openshadinglanguage,tectronics/openshadinglanguage,qdtk/openshadinglanguage,qdtk/openshadinglanguage