fix for ability to lift a CSE out of an assign form when it depends on bindings in the assign and fuzz infra for testing

[prozacchiwawa]

First, the bug fix part is relatively small.
This might need breaking up, but it's a good place to bring in fuzz testing infra that allows us to do more.
A good bit of what's written in the regression part of the CSE fuzz test will be folded into common fuzz infrastructure too.
The fuzz infra added has 2 layers:

1. Core part in src/compiler/fuzz.rs which is a simple runner for a rule based expression expander.
2. Extra parts are in src/tests/compiler/fuzz.rs which adds chialisp specific support.

[coveralls]

Pull Request Test Coverage Report for Build 8851168455

Details

• 110 of 137 (80.29%) changed or added relevant lines in 5 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.1%) to 82.931%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
src/compiler/optimize/above22.rs	14	17	82.35%
src/compiler/comptypes.rs	6	12	50.0%
src/compiler/optimize/cse.rs	80	98	81.63%

Totals
Change from base Build 8835428455:	0.1%
Covered Lines:	15173
Relevant Lines:	18296

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💛 - Coveralls