Fix for <fbt> with local import

Fbt violates the JSX spec by using a lowercase function as a tagname, even 
though lowercase names are reserved for builtins. Here we detect cases where 
there is an `<fbt>` tag where `fbt` is a local identifier and throw a todo.

compiler/packages/babel-plugin-react-forget/src/HIR/BuildHIR.ts

@@ -2044,6 +2044,21 @@ function lowerExpression(
         }
         props.push({ kind: "JsxAttribute", name: propName, place: value });
       }
+      if (tag.kind === "BuiltinTag" && tag.name === "fbt") {
+        const openingIdentifier = opening.get("name");
+        const tagIdentifier = openingIdentifier.isJSXIdentifier()
+          ? builder.resolveIdentifier(openingIdentifier)
+          : null;
+        if (tagIdentifier != null) {
+          CompilerError.throwTodo({
+            reason: `Support <fbt> tags where 'fbt' is a local variable instead of a global`,
+            loc: openingIdentifier.node.loc ?? GeneratedSource,
+            description: null,
+            suggestions: null,
+          });
+        }
+      }
+
       let children: Array<Place>;
       if (tag.kind === "BuiltinTag" && tag.name === "fbt") {
         children = expr

compiler/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/fbt/error.todo-locally-require-fbt.expect.md

@@ -0,0 +1,25 @@
+
+## Input
+
+```javascript
+function Component(props) {
+  const fbt = require("fbt");
+
+  return <fbt desc="Description">{"Text"}</fbt>;
+}
+
+```
+
+
+## Error
+
+```
+  2 |   const fbt = require("fbt");
+  3 |
+> 4 |   return <fbt desc="Description">{"Text"}</fbt>;
+    |           ^^^ [ReactForget] Todo: Support <fbt> tags where 'fbt' is a local variable instead of a global (4:4)
+  5 | }
+  6 |
+```
+          
+      

compiler/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/fbt/error.todo-locally-require-fbt.js

@@ -0,0 +1,5 @@
+function Component(props) {
+  const fbt = require("fbt");
+
+  return <fbt desc="Description">{"Text"}</fbt>;
+}