Ensure extension flags are flattened in the Cmm phase If we start with a .cmmcpp file then they don't get flattened in the CmmCpp phase, as we don't run that phase.
Ensure extension flags are flattened in the Cmm phase
If we start with a .cmmcpp file then they don't get flattened in
the CmmCpp phase, as we don't run that phase.

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