[LICM][NFC] Add tests from D50730
[LICM][NFC] Add tests from D50730

Landing tests so corresponding change can show effects clearly.  see
D50730 [AST] Generalize argument specific aliasing



git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@340243 91177308-0d34-0410-b5e6-96231b3b80d8

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