Support more cases of reassignment within value blocks

Fixes T175283039 — it's totally fine to have a StoreLocal as an instruction in a 
value block, so long as its a reassignment.

compiler/packages/babel-plugin-react-forget/src/ReactiveScopes/CodegenReactiveFunction.ts

@@ -1752,13 +1752,29 @@ function codegenInstructionValue(
       );
       break;
     }
+    case "StoreLocal": {
+      CompilerError.invariant(
+        instrValue.lvalue.kind === InstructionKind.Reassign,
+        {
+          reason: `Unexpected StoreLocal in codegenInstructionValue`,
+          description: null,
+          loc: instrValue.loc,
+          suggestions: null,
+        }
+      );
+      value = t.assignmentExpression(
+        "=",
+        codegenLValue(cx, instrValue.lvalue.place),
+        codegenPlaceToExpression(cx, instrValue.value)
+      );
+      break;
+    }
     case "ReactiveFunctionValue":
     case "Memoize":
     case "Debugger":
     case "DeclareLocal":
     case "DeclareContext":
     case "Destructure":
-    case "StoreLocal":
     case "ObjectMethod":
     case "StoreContext": {
       CompilerError.invariant(false, {

compiler/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/error.todo-reassign-in-while-loop-condition.expect.md

@@ -1,38 +0,0 @@
-
-## Input
-
-```javascript
-import { makeArray } from "shared-runtime";
-
-// @flow
-function Component() {
-  const items = makeArray(0, 1, 2);
-  let item;
-  let sum = 0;
-  while ((item = items.pop())) {
-    sum += item;
-  }
-  return [sum];
-}
-
-export const FIXTURE_ENTRYPOINT = {
-  fn: Component,
-  params: [{}],
-};
-
-```
-
-
-## Error
-
-```
-   6 |   let item;
-   7 |   let sum = 0;
->  8 |   while ((item = items.pop())) {
-     |           ^^^^ [ReactForget] Invariant: Unexpected StoreLocal in codegenInstructionValue (8:8)
-   9 |     sum += item;
-  10 |   }
-  11 |   return [sum];
-```
-          
-      

compiler/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/reassign-in-while-loop-condition.expect.md

@@ -0,0 +1,59 @@
+
+## Input
+
+```javascript
+import { makeArray } from "shared-runtime";
+
+// @flow
+function Component() {
+  const items = makeArray(0, 1, 2);
+  let item;
+  let sum = 0;
+  while ((item = items.pop())) {
+    sum += item;
+  }
+  return [items, sum];
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: Component,
+  params: [{}],
+};
+
+```
+
+## Code
+
+```javascript
+import { unstable_useMemoCache as useMemoCache } from "react";
+import { makeArray } from "shared-runtime";
+
+// @flow
+function Component() {
+  const $ = useMemoCache(1);
+  let t0;
+  if ($[0] === Symbol.for("react.memo_cache_sentinel")) {
+    const items = makeArray(0, 1, 2);
+    let item;
+    let sum = 0;
+    while ((item = items.pop())) {
+      sum = sum + item;
+    }
+
+    t0 = [items, sum];
+    $[0] = t0;
+  } else {
+    t0 = $[0];
+  }
+  return t0;
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: Component,
+  params: [{}],
+};
+
+```
+      
+### Eval output
+(kind: ok) [[],3]

compiler/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/reassign-in-while-loop-condition.js

@@ -8,7 +8,7 @@ function Component() {
   while ((item = items.pop())) {
     sum += item;
   }
-  return [sum];
+  return [items, sum];
 }
 
 export const FIXTURE_ENTRYPOINT = {