Sync to upstream/release/604

[andyfriesen]

New Solver

• New algorithm for inferring the types of locals that have no annotations. This
  algorithm is very conservative by default, but is augmented with some control
  flow awareness to handle most common scenarios.
• Fix bugs in type inference of tables
• Improve performance of by switching out standard C++ containers for DenseHashMap
• Infrastructure to support clearer error messages in strict mode

Native Code Generation

• Fix a lowering issue with buffer.writeu8 and 0x80-0xff values: A constant
  argument wasn't truncated to the target type range and that causes an
  assertion failure in build.mov.
• Store full lightuserdata value in loop iteration protocol lowering
• Add analysis to compute function bytecode distribution
  • This includes a class to analyze the bytecode operator distribution per
    function and a CLI tool that produces a JSON report. See the new cmake
    target Luau.Bytecode.CLI