BenchNative

Hand-written JVM baseline for the two benchmarks in examples/bench-*.

Run with /jim bench. The workloads are identical to the TypeScript versions — the only difference is that this code was written directly in Kotlin and compiled by kotlinc, whereas JIM compiles the TS to JVM bytecode via swc4j. Comparing the two numbers in the same client shows how close JIM's output runs to code a human wrote against the JVM.