const runtime._PTHREAD_KEYS_MAX

2 uses

	runtime (current package)
		defs_darwin_arm64.go#L97: 	_PTHREAD_KEYS_MAX = 512
		sys_darwin_arm64.go#L41: func tlsinit(tlsg *uintptr, tlsbase *[_PTHREAD_KEYS_MAX]uintptr) {

The pages are generated with Golds v0.2.8-preview. (GOOS=darwin GOARCH=arm64)