Heapless devel

CHANGELOG
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- Added some ambient object definitions and linked as prototype (e.g. Number, String, Array)

- Added support for polymorphic function sigs among Intersection types 

- Disabling strong updates. SSA vars that correspond to the same source variable will have the same raw type.  

- Variable type annotations with no refinements are K-vared.

- Allowing uninitialized variable declarations.

BENCHMARKS
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- Done resistor.js: a few (minor) parts that are not supported yet are noted as TODO