message: Add isFunctionDeclarationOrArrowFunction()
diff: @@ -6,6 +6,7 @@ import { last } from "../array";
  export {
  isClassPropertyIdentifier,
  isVariableDeclarationIdentifier,
  + isFunctionDeclarationOrArrowFunction,
  isFunctionCallIdentifier,
  isJSXPartialElement,
  isPropertyOfMemberExpression,
  @@ -41,6 +42,12 @@ function isVariableDeclarationIdentifier(path: NodePath): boolean {
  return t.isVariableDeclarator(path.parent) && t.isIdentifier(path);
  }
  +function isFunctionDeclarationOrArrowFunction(
  + node: t.Node
  +): node is t.FunctionDeclaration | t.ArrowFunctionExpression {
  + return t.isFunctionDeclaration(node) || t.isArrowFunctionExpression(node);
  +}
  +
  function isFunctionCallIdentifier(path: NodePath): boolean {
  return t.isCallExpression(path.parent) && path.parent.callee === path.node;
  }
  