Add hoisting support for ref components

Summary:
This adds hoisting logic to components with refs. This is needed since the `ref` transform adds a `const ... = React.forwardRef(...);`. This inserted variable declaration has different hoisting semantics vs a function declaration of a component. So this change finds any references and hoists the statement above the first reference. e.g.
```
Bar;
unrelated;

Bar;
component Bar(foo: string, ref: Ref) {}
```
Transforms into:
```
const Bar = React.forwardRef(Bar_withRef);
Bar;
unrelated;

Bar;
function Bar_withRef({
  foo
}: $ReadOnly<{...}>, ref: Ref): React.Node {}"
```

The way this works is when a component statement is found with a `ref` param we walk from the first statement to the component traversing the full tree, if a component reference is found we abort walking and return the position. Then inject the forwardRef statement before that position.

Reviewed By: mvitousek, jbrown215

Differential Revision: D48247491

fbshipit-source-id: 77714765f04bba0cb369389e364b0981a9075419

tools/hermes-parser/js/hermes-parser/__tests__/ComponentDeclaration-test.js

@@ -326,4 +326,71 @@ switch (thing) {
       `);
     });
   });
+
+  describe('ref and normal params with hoisting', () => {
+    const code = `
+Bar;
+unrelated;
+someSideEffect(Foo);
+unrelated;
+
+component Foo(foo: string, ref: Ref) {}
+
+Bar;
+component Bar(foo: string, ref: Ref) {}
+    `;
+
+    test('ESTree', async () => {
+      expect(await printForSnapshotESTree(code)).toBe(code.trim());
+      expect(await parseForSnapshotESTree(code)).toMatchSnapshot();
+    });
+
+    test('Babel', async () => {
+      expect(await parseForSnapshotBabel(code)).toMatchSnapshot();
+      expect(await printForSnapshotBabel(code)).toMatchInlineSnapshot(`
+        "const Bar = React.forwardRef(Bar_withRef);
+        Bar;
+        unrelated;
+        const Foo = React.forwardRef(Foo_withRef);
+        someSideEffect(Foo);
+        unrelated;
+
+        function Foo_withRef({
+          foo
+        }: $ReadOnly<{...}>, ref: Ref): React.Node {}
+
+        Bar;
+
+        function Bar_withRef({
+          foo
+        }: $ReadOnly<{...}>, ref: Ref): React.Node {}"
+      `);
+    });
+  });
+
+  describe('ref and normal params with hoisting (recursive)', () => {
+    const code = `
+component Foo(bar: mixed = Foo, ref: any) {
+  return null;
+}
+    `;
+
+    test('ESTree', async () => {
+      expect(await printForSnapshotESTree(code)).toBe(code.trim());
+      expect(await parseForSnapshotESTree(code)).toMatchSnapshot();
+    });
+
+    test('Babel', async () => {
+      expect(await parseForSnapshotBabel(code)).toMatchSnapshot();
+      expect(await printForSnapshotBabel(code)).toMatchInlineSnapshot(`
+        "const Foo = React.forwardRef(Foo_withRef);
+
+        function Foo_withRef({
+          bar = Foo
+        }: $ReadOnly<{...}>, ref: any): React.Node {
+          return null;
+        }"
+      `);
+    });
+  });
 });