Keep the view-header test's loops speculative

Module number globals are now proven int32 through their writes, so the test's generator state starts from a value no analysis bounds to keep its loops on the speculative path. Format int32-slots.ts.

packages/compiler/src/ir/int32-slots.ts

@@ -1722,8 +1722,7 @@ export function analyzeInt32Slots(mod: IrModule, inputs: Int32SlotInputs = {}):
         if (s.kind === "assign") {
           boxWrite(s.localId, s.value);
           globalWrite(s.localId, s.value);
-        }
-        else if (s.kind === "varDecl" && s.init) boxWrite(s.localId, s.init);
+        } else if (s.kind === "varDecl" && s.init) boxWrite(s.localId, s.init);
         if (s.kind === "fieldSet") {
           const family = slots.family(s.className, s.field);
           if (!family || !slots.hasFamily(family)) return;

packages/compiler/test/speculative-loop-emission.test.ts

@@ -188,9 +188,10 @@ test("a speculative loop reads its views' header fields once, before its copies"
   // A view held by a const local or by a parameter is the same view in
   // every iteration. Its data pointer is read before the branch to the fast
   // copy, and no copy (ordinary, fast, or the one a failed check resumes
-  // in) reads it again.
+  // in) reads it again. `last` starts from a value no analysis bounds,
+  // so the loops speculate on `l`.
   const llvm = await emitLlvm(`
-let last = 42;
+let last = Number(process.argv[2] ?? "42");
 function fill(array: ArrayBuffer, count: number): void {
   const buf = new Float64Array(array);
   let l = last;