//
//	func Example() { ... }
//	func ExampleF() { ... }
//	func ExampleT() { ... }
//	func ExampleT_M() { ... }
//
// Multiple example functions for a package/type/function/method may be provided by
// appending a distinct suffix to the name. The suffix must start with a
// lower-case letter.
//
//	func Example_suffix() { ... }
//	func ExampleF_suffix() { ... }
//	func ExampleT_suffix() { ... }

		panic("buildStacks")
	}
	for _, pkg := range ld.roots {
		pkg.stack = pkg // sentinel to avoid processing in next loop
		ld.pkgs = append(ld.pkgs, pkg)
	}
	for i := 0; i < len(ld.pkgs); i++ { // not range: appending to ld.pkgs in loop
		pkg := ld.pkgs[i]
		for _, next := range pkg.imports {
			if next.stack == nil {
				next.stack = pkg
				ld.pkgs = append(ld.pkgs, next)
			}
		}