3a4376b8f9
getPtrStride returns 0 when the PtrScev is loop-invariant, and this is not an erroneous value: it returns std::nullopt to communicate that it was not able to find a valid pointer stride. In analyzeLoop, we call getPtrStride with a value_or(0) conflating the zero return value with std::nullopt. Fix this, handling loop-invariant loads correctly.