From jdk/src/java.base/share/classes/java/lang/StackFrameInfo.java:

  40 // Footprint improvement: MemberName::clazz can replace
  41 // StackFrameInfo::declaringClass.

The 'declaringClass' reference can be removed from StackFrameInfo, and instead, StackFrameInfo.getDeclaringClass() can return the clazz from memberName.