Index range cache comparison with strict ordering

Stl set expects element type to have strict ordering. It might define
a==b as !(a<b) && !(b<a). This CL implements strict ordering for
IndexRangeMap.

Test: manual

BUG: 119568237
Change-Id: I3f246b1abccf70963a37900c250871c1a49ee145
2 files changed