Enable $SHBuiltin.moduleFactory optimisation via custom transform option

Summary:
When the custom transform option `unstable_staticHermesOptimizedRequire` is truthy, wrap module factories in

```javascript
$SHBuiltin.moduleFactory(moduleId, factory)
```

This enables a Static Hermes-only optimisation for experimentation.

Changelog:

```javascript
 - **[Experimental]**: Opt-in SHBuiltin module factory optimisation
```

Reviewed By: motiz88

Differential Revision: D73510634

fbshipit-source-id: 2ac94b08d13e453d87abdaae33d9ea0403a7b9e5

Author: robhogan

packages/metro-transform-worker/src/index.js

@@ -129,6 +129,7 @@ export type JsTransformOptions = $ReadOnly<{
   unstable_disableES6Transforms?: boolean,
   unstable_memoizeInlineRequires?: boolean,
   unstable_nonMemoizedInlineRequires?: $ReadOnlyArray<string>,
+  unstable_staticHermesOptimizedRequire?: boolean,
   unstable_transformProfile: TransformProfile,
 }>;
 
@@ -429,6 +430,12 @@ async function transformJS(
         // release. It should be made non-optional in ConfigT or removed in
         // future.
         config.unstable_renameRequire === false,
+        {
+          unstable_useStaticHermesModuleFactory: Boolean(
+            options.customTransformOptions
+              ?.unstable_staticHermesOptimizedRequire,
+          ),
+        },
       ));
     }
   }
@@ -572,7 +579,14 @@ async function transformJSON(
   let code =
     config.unstable_disableModuleWrapping === true
       ? JsFileWrapping.jsonToCommonJS(file.code)
-      : JsFileWrapping.wrapJson(file.code, config.globalPrefix);
+      : JsFileWrapping.wrapJson(
+          file.code,
+          config.globalPrefix,
+          Boolean(
+            options.customTransformOptions
+              ?.unstable_staticHermesOptimizedRequire,
+          ),
+        );
   let map: Array<MetroSourceMapSegmentTuple> = [];
 
   // TODO: When we can reuse transformJS for JSON, we should not derive `minify` separately.
@@ -654,13 +668,22 @@ module.exports = {
     };
     const sourceCode = data.toString('utf8');
 
-    const {unstable_dependencyMapReservedName} = config;
-    if (unstable_dependencyMapReservedName != null) {
-      const position = sourceCode.indexOf(unstable_dependencyMapReservedName);
+    const reservedStrings = [];
+    if (
+      options.customTransformOptions?.unstable_staticHermesOptimizedRequire ==
+      true
+    ) {
+      reservedStrings.push('_$$_METRO_MODULE_ID');
+    }
+    if (config.unstable_dependencyMapReservedName != null) {
+      reservedStrings.push(config.unstable_dependencyMapReservedName);
+    }
+    for (const reservedString of reservedStrings) {
+      const position = sourceCode.indexOf(reservedString);
       if (position > -1) {
         throw new SyntaxError(
           'Source code contains the reserved string `' +
-            unstable_dependencyMapReservedName +
+            reservedString +
             '` at character offset ' +
             position,
         );

packages/metro/src/ModuleGraph/worker/JsFileWrapping.js

@@ -33,6 +33,9 @@ function wrapModule(
   dependencyMapName: string,
   globalPrefix: string,
   skipRequireRename: boolean,
+  {
+    unstable_useStaticHermesModuleFactory = false,
+  }: $ReadOnly<{unstable_useStaticHermesModuleFactory?: boolean}> = {},
 ): {
   ast: BabelNodeFile,
   requireName: string,
@@ -43,7 +46,19 @@ function wrapModule(
     dependencyMapName,
   );
   const factory = functionFromProgram(fileAst.program, params);
-  const def = t.callExpression(t.identifier(`${globalPrefix}__d`), [factory]);
+
+  const def = t.callExpression(t.identifier(`${globalPrefix}__d`), [
+    unstable_useStaticHermesModuleFactory
+      ? t.callExpression(
+          t.memberExpression(
+            t.identifier('$SHBuiltin'),
+            t.identifier('moduleFactory'),
+          ),
+          [t.identifier('_$$_METRO_MODULE_ID'), factory],
+        )
+      : factory,
+  ]);
+
   const ast = t.file(t.program([t.expressionStatement(def)]));
 
   // `require` doesn't need to be scoped when Metro serializes to iife because the local function
@@ -64,19 +79,31 @@ function jsonToCommonJS(source: string): string {
   return `module.exports = ${source};`;
 }
 
-function wrapJson(source: string, globalPrefix: string): string {
+function wrapJson(
+  source: string,
+  globalPrefix: string,
+  unstable_useStaticHermesModuleFactory?: boolean = false,
+): string {
   // Unused parameters; remember that's wrapping JSON.
   const moduleFactoryParameters = buildParameters(
     '_importDefaultUnused',
     '_importAllUnused',
     '_dependencyMapUnused',
   );
 
-  return [
-    `${globalPrefix}__d(function(${moduleFactoryParameters.join(', ')}) {`,
+  const factory = [
+    `function(${moduleFactoryParameters.join(', ')}) {`,
     `  ${jsonToCommonJS(source)}`,
-    '});',
+    '}',
   ].join('\n');
+
+  return (
+    `${globalPrefix}__d(` +
+    (unstable_useStaticHermesModuleFactory
+      ? '$SHBuiltin.moduleFactory(_$$_METRO_MODULE_ID, ' + factory + ')'
+      : factory) +
+    ');'
+  );
 }
 
 function functionFromProgram(