Performance regression on Chrome Canary 69

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No description provided.

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On Chrome Stable Version 67.0.3396.99 (Official Build) (64-bit):
With V8 6.7.288.46

On Chrome Canary Version 69.0.3495.0 (Official Build) canary (64-bit)
with V8 6.9.423

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Also happens on Chrome Dev and Canary Channels.

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When comparing on Chrome Canary vs Stable, the lexer seems to be about the same speed
and the parser seems to be almost x4 slower

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Looks like the performance more than halved with V8 6.9.xxx
But the other parsers used in this benchmark were not affected or only slightly affected.
Perhaps the major regression is in some JavaScript patterns common in Chevrotain
but more rare in the other parsers.

Random thoughts on what such flows may be:

• Using Noop pattern to dynamically eliminate function invocations for unused flows (e.g. CST creation / error recovery).
• Using 32bit keys created using bitwise operations for caching.
• Using a ton of anonymous functions / callbacks.

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Opened a bug here:
https://bugs.chromium.org/p/v8/issues/detail?id=7952