[test] Add test for lambda that conditionally captures ref

Conditionally captured refs are correctly added to dependency list of the 
lambda.

compiler/forget/src/__tests__/fixtures/hir/capturing-function-conditional-capture-mutate.expect.md

@@ -0,0 +1,54 @@
+
+## Input
+
+```javascript
+function component(a, b) {
+  let z = { a };
+  let y = b;
+  let x = function () {
+    if (y) {
+      mutate(z);
+    }
+  };
+  return x;
+}
+
+```
+
+## Code
+
+```javascript
+function component(a, b) {
+  const $ = React.unstable_useMemoCache(5);
+  const c_0 = $[0] !== a;
+  let t0;
+  if (c_0) {
+    t0 = { a };
+    $[0] = a;
+    $[1] = t0;
+  } else {
+    t0 = $[1];
+  }
+  const z = t0;
+  const y = b;
+  const c_2 = $[2] !== y;
+  const c_3 = $[3] !== z;
+  let t1;
+  if (c_2 || c_3) {
+    t1 = function () {
+      if (y) {
+        mutate(z);
+      }
+    };
+    $[2] = y;
+    $[3] = z;
+    $[4] = t1;
+  } else {
+    t1 = $[4];
+  }
+  const x = t1;
+  return x;
+}
+
+```
+      

compiler/forget/src/__tests__/fixtures/hir/capturing-function-conditional-capture-mutate.js

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+function component(a, b) {
+  let z = { a };
+  let y = b;
+  let x = function () {
+    if (y) {
+      mutate(z);
+    }
+  };
+  return x;
+}