Incorrect work #each with 'alert' as item name

[NikolayMakhonin]

See this repl

This code:

{#each alerts as alert}
	<p>{alert}</p>
{/each}

display the system alert() function instead the alerts item:

function alert() { [native code] }
function alert() { [native code] }

Same problem with many system names such as window, document, history, ...

It turns out that many good variable names are banned, also that leads to implicit errors, because I expect that local variables will override the global

Server rendering works correctly, probably because there are no such global variables