allow keyword in object/class property names with Flow type parameters (#145)

src/plugins/flow.js

@@ -888,6 +888,17 @@ export default function (instance) {
     };
   });
 
+  // ensure that inside property names, < isn't interpreted as JSX, but as a type parameter
+  instance.extend("parsePropertyName", function (inner) {
+    return function (prop) {
+      const oldInType = this.state.inType;
+      this.state.inType = true;
+      const out = inner.call(this, prop);
+      this.state.inType = oldInType;
+      return out;
+    };
+  });
+
   // ensure that inside flow types, we bypass the jsx parser plugin
   instance.extend("readToken", function (inner) {
     return function (code) {