fix(javascript): keep spread child argv counts unknown (#2748)

* fix(javascript): keep spread child argv counts unknown

* test(javascript): own runtime controls and tighten evidence assertions

* test(apple): keep dyld slice regression portable

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Co-authored-by: hhang <169027046+xu91102@users.noreply.github.com>

src/domain/javascript/javascriptSemanticChildProcesses.ts

@@ -339,7 +339,10 @@ const spawnOptions = (candidate: SpawnCandidate): t.ObjectExpression | null => {
 const spawnArgvCount = (candidate: SpawnCandidate): number | null => {
   if (candidate.method === "exec") return null;
   const args = candidate.node.arguments[1];
-  return t.isArrayExpression(args) ? args.elements.length : null;
+  return t.isArrayExpression(args) &&
+    !args.elements.some((element) => t.isSpreadElement(element))
+    ? args.elements.length
+    : null;
 };
 
 const objectHasProperty = (