Move HashSet-wasm to first, worst, average scoring

Same steps as for the other Wasm line items:
- Move files to subdirectory.
- Rebuild with up-to-date Emscripten.
- Reduce single iteration time, so that we can run multiple iterations (a single iteration before took ~300ms, now ~30ms).
- Checked that we spend roughly the same amount of CPU samples in the top-tier and that overall profiles look similar.

Author: danleh

JetStreamDriver.js

@@ -1952,13 +1952,14 @@ const BENCHMARKS = [
         testGroup: GeneratorsGroup,
     }),
     // Wasm
-    new WasmLegacyBenchmark({
+    new WasmEMCCBenchmark({
         name: "HashSet-wasm",
         files: [
-            "./wasm/HashSet.js"
+            "./wasm/HashSet/build/HashSet.js",
+            "./wasm/HashSet/benchmark.js"
         ],
         preload: {
-            wasmBinary: "./wasm/HashSet.wasm"
+            wasmBinary: "./wasm/HashSet/build/HashSet.wasm"
         },
         testGroup: WasmGroup
     }),