As per the discussion on D58375, we disable test that have optimizations under the new PM. This patch adds -fno-experimental-new-pass-manager to RUNS that:
- Already run with optimizations (-O1 or higher) that were missed in D58375.
- Explicitly test new PM behavior along side some new PM RUNS, but are missing this flag if new PM is enabled by default.
- Specify -O without the number. Based on getOptimizationLevel(), it seems the default is 2, and the IR appears to be the same when changed to -O2, so update the test to explicitly say -O2 and provide -fno-experimental-new-pass-manager`.