Two fixes.  First, stop using the ugly shouldSubstituteIndVar method.
Two fixes.  First, stop using the ugly shouldSubstituteIndVar method.

Second, disable substitution of quadratic addrec expressions to avoid putting
multiplies in loops!


git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@14358 91177308-0d34-0410-b5e6-96231b3b80d8

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