Enhance the assertion mechanisms in place to make it easier to catch when we fail to place all the blocks of a loop. Currently this is happening for unnatural loops, and this logic helps more immediately point to the problem.
Enhance the assertion mechanisms in place to make it easier to catch
when we fail to place all the blocks of a loop. Currently this is
happening for unnatural loops, and this logic helps more immediately
point to the problem.

git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@144504 91177308-0d34-0410-b5e6-96231b3b80d8

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