// This file defines the PassManager class. This class is used to hold,
// maintain, and optimize execution of Passes. The PassManager class ensures
// that analysis results are available before a pass runs, and that Pass's are
// This file defines the PassManager class. This class is used to hold,
// maintain, and optimize execution of Passes. The PassManager class ensures
// that analysis results are available before a pass runs, and that Pass's are