I've noted the rationale for this in the comment, and in the attached bug.
This should save about 4-8 bytes of memory (on the 64bit server JVM depending on if compressed object pointers are on) per object with extensions. And 4 bytes on Android.
PiperOrigin-RevId: 661900014
pull/17785/head
Mark Hansen7 months agocommitted byCopybara-Service