Sync to upstream/release/602

[aatxe]

What's changed?

• Fixed a bug in type cloning by maintaining persistent types.
• We now parse imprecise integer literals to report the imprecision as a warning to developers.
• Add a compiler flag to specify the name of the statistics output file.

New type solver

• Renamed ConstraintGraphBuilder to ConstraintGenerator
• LValues now take into account the type being assigned during constraint generation.
• Normalization performance has been improved by 33% by replacing the an internal usage of std::unordered_set with DenseHashMap.
• Normalization now has a helper to identify types that are equivalent to unknown, which is being used to fix some bugs in subtyping.
• Uses of the old unifier in the new type solver have been eliminated.
• Improved error explanations for subtyping errors in TypeChecker2.

Native code generation

• Expanded some of the statistics recorded during compilation to include the number of instructions and blocks.
• Introduce instruction and block count limiters for controlling what bytecode is translated into native code.
• Implement code generation for byteswap instruction.

Internal Contributors

Co-authored-by: Aaron Weiss [email protected]
Co-authored-by: Alexander McCord [email protected]
Co-authored-by: Andy Friesen [email protected]
Co-authored-by: Aviral Goel [email protected]
Co-authored-by: Lily Brown [email protected]