Completions panic (nil pointer) in JSDoc union return type of method with params

[DanielRosenwasser]

/**
 * @type {{
 *   (input: string): X|Y/*$*/
 * }}
 */
let x;

Request completions at $.

error] panic handling request textDocument/completion: runtime error: invalid memory address or nil pointer dereference
goroutine 1757 [running]:
runtime/debug.Stack()
	runtime/debug/stack.go:26 +0x64
github.com/microsoft/typescript-go/internal/lsp.(*Server).recover(0x40001a0008, 0x401010ae70)
	github.com/microsoft/typescript-go/internal/lsp/server.go:743 +0x40
panic({0x7ff62b1b4980?, 0x7ff62bcd3ff0?})
	runtime/panic.go:783 +0x120
github.com/microsoft/typescript-go/internal/checker.(*Checker).getSignatureFromDeclaration(0x400fa7a008, 0x400400afc0)
	github.com/microsoft/typescript-go/internal/checker/checker.go:19268 +0x298
github.com/microsoft/typescript-go/internal/checker.(*Checker).TryGetThisTypeAtEx(0x400fa7a008, 0x4004ba3a00, 0x0, 0x7ff62afebd60?)
	github.com/microsoft/typescript-go/internal/checker/checker.go:11782 +0x130
github.com/microsoft/typescript-go/internal/ls.(*LanguageService).getCompletionData.func17()
	github.com/microsoft/typescript-go/internal/ls/completions.go:1497 +0x4e0
github.com/microsoft/typescript-go/internal/ls.(*LanguageService).getCompletionData.func18(...)
	github.com/microsoft/typescript-go/internal/ls/completions.go:1541
github.com/microsoft/typescript-go/internal/ls.(*LanguageService).getCompletionData(0x400fa76000, {0x7ff62b673ec8, 0x400f35c090}, 0x400fa7a008, 0x4007c79508, 0x2b, 0x4000312f00)
	github.com/microsoft/typescript-go/internal/ls/completions.go:1574 +0x16e0
github.com/microsoft/typescript-go/internal/ls.(*LanguageService).getCompletionsAtPosition(0x400fa76000, {0x7ff62b673ec8, 0x400f35c090}, 0x4007c79508, 0x2b, 0x0)
	github.com/microsoft/typescript-go/internal/ls/completions.go:345 +0x284
github.com/microsoft/typescript-go/internal/ls.(*LanguageService).ProvideCompletion(0x400fa76000, {0x7ff62b673ec8, 0x400f35c090}, {0x4005ee8018?, 0x400f35c090?}, {0x5ee8018?, 0x40?}, 0x40100b2000)
	github.com/microsoft/typescript-go/internal/ls/completions.go:45 +0xa0
github.com/microsoft/typescript-go/internal/lsp.(*Server).handleCompletion(0x500f0f920?, {0x7ff62b673ec8?, 0x400f35c090?}, 0x4005ee8018?, 0x40084a1de8?)
	github.com/microsoft/typescript-go/internal/lsp/server.go:1053 +0x3c
github.com/microsoft/typescript-go/internal/lsp.init.func1.registerLanguageServiceWithAutoImportsRequestHandler[...].28({0x7ff62b673ec8, 0x400f35c090}, 0x401010ae70)
	github.com/microsoft/typescript-go/internal/lsp/server.go:646 +0xf0
github.com/microsoft/typescript-go/internal/lsp.(*Server).handleRequestOrNotification(0x40001a0008, {0x7ff62b673f00?, 0x400def4000?}, 0x401010ae70)
	github.com/microsoft/typescript-go/internal/lsp/server.go:502 +0x148
github.com/microsoft/typescript-go/internal/lsp.(*Server).dispatchLoop.func1()
	github.com/microsoft/typescript-go/internal/lsp/server.go:404 +0x34
created by github.com/microsoft/typescript-go/internal/lsp.(*Server).dispatchLoop in goroutine 10
	github.com/microsoft/typescript-go/internal/lsp/server.go:424 +0x7a0