[NewPM] Redesign of PreserveCFG Checker

The reason for the NewPM redesign is described in the commit
  cba3e783389a: [NewPM] Disable PreservedCFGChecker ...

The checker introduces an internal custom CFG analysis that tracks
current up-to date CFG snapshot. The analysis is invalidated along
any other CFG related analysis (the key is CFGAnalyses). If the CFG
analysis is not invalidated at a functional pass exit then the checker
asserts that the CFG snapshot taken from this analysis is equals to
a snapshot of the current CFG.

Along the way:
- the function CFG::printDiff() is simplified by removing function
  name calculation. The name is printed by the caller;
- fixed CFG invalidated condition (see CFG::invalidate());
- StandardInstrumentations::registerCallbacks() gets additional
  optional parameter of type FunctionAnalysisManager*, which is
  needed by the checker to get the custom CFG analysis;
- several PM related tests updated to explicitly set
  -verify-cfg-preserved=1 as they need.

This patch is safe to land as the CFGChecker is left switched off
(the options -verify-cfg-preserved is false by default). It will be
switched on by a separate patch to minimize possible reverts.

Reviewed By: skatkov, kuhar

Differential Revision: https://reviews.llvm.org/D91327

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