Hermes lacks Math.sumPrecise, a TC39 Stage 3 proposal for high-precision floating-point summation.

Problem:

[1e20, 1, -1e20].reduce((a, b) => a + b, 0)  // Returns 0, loses precision
Math.sumPrecise([1e20, 1, -1e20])            // Would return 1

Use cases:

• Financial calculations in React Native apps
• Scientific computing requiring numerical stability
• Data aggregation without accumulated rounding errors

Specification: https://github.com/tc39/proposal-math-sum (Stage 3)

Implementation ready: I have a working implementation using Shewchuk's algorithm. Should I proceed with a PR?