MachineModuleInfo should migrate away from Uniquevector.

[llvmbot]

Bugzilla Link	1162
Resolution	WORKSFORME
Resolved on	Sep 21, 2008 16:18
Version	trunk
OS	All
Reporter	LLVM Bugzilla Contributor

Extended Description

UniqueVector is very expensive: its cost is the sum of the cost of maintaining both the map and vector, it
has high complexity, high constant factors, and produces a lot of malloc traffic. It should be avoided.

[lattner]

This is only used in MachineModuleInfo for a couple of high level things, it isn't a real perf issue.