Fix LinkFieldsComparator.

Define order for primitive types with the same sizes.
Previously, the comparator would consider the fields equal
so the order would depend on std::sort() implementation.
Changing the STL implementation could silently change the
field offsets. (And, unlike std::stable_sort(), the
std::sort() doesn't even need to be deterministic.)

(cherry picked from commit d577748c041aa6df599218f3cb31697ecf032730)

Change-Id: I9b769d023864aa36c52918c7c3dd11c0f6b8f40e
2 files changed