[λ] Add test for nested function declaration that captures a var

compiler/forget/src/__tests__/fixtures/hir/capturing-var-in-nested-func-decl.expect.md

@@ -0,0 +1,57 @@
+
+## Input
+
+```javascript
+function component(a) {
+  let z = { a };
+  let x = function () {
+    function t() {
+      z;
+    }
+    t();
+  };
+  return x;
+}
+
+```
+
+## Code
+
+```javascript
+function component(a) {
+  const $ = React.useMemoCache();
+  const c_0 = $[0] !== a;
+  let z;
+  if (c_0) {
+    z = {
+      a: a,
+    };
+    $[0] = a;
+    $[1] = z;
+  } else {
+    z = $[1];
+  }
+
+  const c_2 = $[2] !== z;
+  let x;
+
+  if (c_2) {
+    x = function () {
+      function t() {
+        z;
+      }
+
+      t();
+    };
+
+    $[2] = z;
+    $[3] = x;
+  } else {
+    x = $[3];
+  }
+
+  return x;
+}
+
+```
+      

compiler/forget/src/__tests__/fixtures/hir/capturing-var-in-nested-func-decl.js

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+function component(a) {
+  let z = { a };
+  let x = function () {
+    function t() {
+      z;
+    }
+    t();
+  };
+  return x;
+}