• Add a few things I missed based on yield expression.
• Add a transform to generate working JavaScript.

Known Issues

• Will not work correctly if you use --importHelpers

• Added the try-expression-proposal syntax to the parser basically copying the yield syntax.
• Does NOT include any polyfill or helper function, just passes the syntax straight through to Javascript.

• Added the expression syntax and typing to the parser, mostly copying yield expression code, so it should behave the same. This is more greedy than await.
• BUG: I didn't completely copy the yield code, as I was using await first. So here are some places it doesn't work yet where yield does.
  • As an arrow function body () => try 1
  • In an array [try 1]
  • As an argument test(try 1)