Allow keywords in object/class property names with Flow type parameters

src/plugins/flow.js

@@ -885,6 +885,17 @@ 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) {

test/fixtures/flow/type-parameter-declaration/class-method-reserved-word/actual.js

@@ -0,0 +1,10 @@
+class X {
+  foobar<T>() {}
+  delete<T>() {}
+  yield<T>() {}
+  do<T>() {}
+  static foobar<T>() {}
+  static delete<T>() {}
+  static yield<T>() {}
+  static do<T>() {}
+};