export as

# Feature Request
## Overview
would be nice to export functions (and other stuff?) under a different name, not limited to valid javascript identifiers..

# Impact
Some implementations might require modules to export functions under specific names, which might be a javascript keyword or contain special characters.

## Details
Maybe something like this?

export as "break" function exit():void { ... };
// or
export function exit():void { ... } as "break";
// or
function exit():void { ... }
export exit as "break";

No files or tests are named. Start by locating the compiler handling for export declarations, then trace how exported names are emitted in WebAssembly. Define the supported syntax and add coverage for keyword and special-character names before considering the work done.

Written by the indexing model from the issue text.