[FeatureFlag] Toggle enableTreatHooksAsFunctions default to true

--- 

Toggle default to true, since this should be a no-op refactor. 

Tests: 

- test fixtures 

- ran on Store + - and saw no difference in compiled output 

- [diff](P744101621) with 
`enableTreatHooksAsFunctions=false` 

- [diff](P744105565) with 
`enableTreatHooksAsFunctions=true`

compiler/forget/packages/snap/src/compiler-worker.ts

@@ -94,7 +94,7 @@ export async function compile(
     let panicOnBailout = true;
     let memoizeJsxElements = true;
     let enableAssumeHooksFollowRulesOfReact = false;
-    let enableTreatHooksAsFunctions = false;
+    let enableTreatHooksAsFunctions = true;
     if (firstLine.indexOf("@forgetDirective") !== -1) {
       enableOnlyOnUseForgetDirective = true;
     }
@@ -125,8 +125,8 @@ export async function compile(
     if (firstLine.indexOf("@enableAssumeHooksFollowRulesOfReact true") !== -1) {
       enableAssumeHooksFollowRulesOfReact = true;
     }
-    if (firstLine.indexOf("@enableTreatHooksAsFunctions true") !== -1) {
-      enableTreatHooksAsFunctions = true;
+    if (firstLine.indexOf("@enableTreatHooksAsFunctions false") !== -1) {
+      enableTreatHooksAsFunctions = false;
     }
 
     const language = parseLanguage(firstLine);

compiler/forget/src/HIR/Environment.ts

@@ -99,7 +99,7 @@ export type EnvironmentConfig = Partial<{
    * Enabling this may change inference to have a higher confidence level
    * and create more bailouts (e.g. for mutable effects to immutable values).
    *
-   * Defaults to false
+   * Defaults to true
    */
   enableTreatHooksAsFunctions: boolean;
 }>;
@@ -149,7 +149,7 @@ export class Environment {
     this.enableAssumeHooksFollowRulesOfReact =
       config?.enableAssumeHooksFollowRulesOfReact ?? false;
     this.enableTreatHooksAsFunctions =
-      config?.enableTreatHooksAsFunctions ?? false;
+      config?.enableTreatHooksAsFunctions ?? true;
     this.#contextIdentifiers = contextIdentifiers;
   }
 

compiler/forget/src/__tests__/fixtures/compiler/unknown-hooks-do-not-assert.expect.md

@@ -2,8 +2,12 @@
 ## Input
 
 ```javascript
-// @enableTreatHooksAsFunctions true
-// (enableAssumeHooksFollowRulesOfReact=false)
+// Forget currently bails out when it detects a potential mutation (Effect.Mutate)
+// to an immutable value. This should not apply to unknown / untyped hooks.
+
+// Default feature flags:
+// enableAssumeHooksFollowRulesOfReact=false
+// enableTreatHooksAsFunctions=true
 function Component(props) {
   const x = useUnknownHook1(props);
   const y = useUnknownHook2(x);
@@ -15,8 +19,12 @@ function Component(props) {
 ## Code
 
 ```javascript
-// @enableTreatHooksAsFunctions true
-// (enableAssumeHooksFollowRulesOfReact=false)
+// Forget currently bails out when it detects a potential mutation (Effect.Mutate)
+// to an immutable value. This should not apply to unknown / untyped hooks.
+
+// Default feature flags:
+// enableAssumeHooksFollowRulesOfReact=false
+// enableTreatHooksAsFunctions=true
 function Component(props) {
   const x = useUnknownHook1(props);
   const y = useUnknownHook2(x);

compiler/forget/src/__tests__/fixtures/compiler/unknown-hooks-do-not-assert.js

@@ -1,5 +1,9 @@
-// @enableTreatHooksAsFunctions true
-// (enableAssumeHooksFollowRulesOfReact=false)
+// Forget currently bails out when it detects a potential mutation (Effect.Mutate)
+// to an immutable value. This should not apply to unknown / untyped hooks.
+
+// Default feature flags:
+// enableAssumeHooksFollowRulesOfReact=false
+// enableTreatHooksAsFunctions=true
 function Component(props) {
   const x = useUnknownHook1(props);
   const y = useUnknownHook2(x);

compiler/forget/src/__tests__/test-utils/generateTestsFromFixtures.ts

@@ -103,7 +103,7 @@ export default function generateTestsFromFixtures(
         let panicOnBailout = true;
         let memoizeJsxElements = true;
         let enableAssumeHooksFollowRulesOfReact = false;
-        let enableTreatHooksAsFunctions = false;
+        let enableTreatHooksAsFunctions = true;
 
         if (inputFile != null) {
           input = fs.readFileSync(inputFile, "utf8");
@@ -153,8 +153,8 @@ export default function generateTestsFromFixtures(
           ) {
             enableAssumeHooksFollowRulesOfReact = true;
           }
-          if (lines[0]!.indexOf("@enableTreatHooksAsFunctions true") !== -1) {
-            enableTreatHooksAsFunctions = true;
+          if (lines[0]!.indexOf("@enableTreatHooksAsFunctions false") !== -1) {
+            enableTreatHooksAsFunctions = false;
           }
         }