New pass manager driver passes DebugPM (-debug-pass-manager) flag into
individual PassManager constructors in order to enable debug logging.
FunctionToLoopPassAdaptor has its own internal LoopCanonicalizationPM
which never gets its debug logging enabled and that means canonicalization
passes like LoopSimplify are never present in -debug-pass-manager output.
Extending FunctionToLoopPassAdaptor's constructor and
createFunctionToLoopPassAdaptor wrapper with an optional
boolean DebugLogging argument.
Passing debug-logging flags there as appropriate.