Add Closure externs for growable and resizable properties

[kleisauke]

Prevents Closure compiler from mangling the resizable and
growable properties accessed on HEAP8.buffer.

[kleisauke]

See:

emscripten/src/runtime_common.js

Lines 149 to 156 in f351c42

	// If we already have a heap that is resizeable/growable buffer we don't
	// need to do anything in updateMemoryViews.
	#if SHARED_MEMORY
	if (HEAP8?.buffer?.growable) return;
	#else
	if (HEAP8?.buffer?.resizable) return;
	#endif
	var b = getMemoryBuffer();

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/ArrayBuffer/resizable
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/SharedArrayBuffer/growable