inline trivial constructors / methods

Summary:
@public

inlines some trivial constructors, destructors, and methods.

Reviewed By: astreet

Differential Revision: D8912691

fbshipit-source-id: 79840ef3322676deebed99391390d6c1796963b5

yoga/YGStyle.cpp

@@ -98,9 +98,3 @@ bool YGStyle::operator==(const YGStyle& style) {
 
   return areNonFloatValuesEqual;
 }
-
-bool YGStyle::operator!=(YGStyle style) {
-  return !(*this == style);
-}
-
-YGStyle::~YGStyle() {}