Remove 'async-await' usage from the dart2js compiler.

Remove 'async-await' usage from the dart2js compiler.

BUG=
R=floitsch@google.com

Committed: https://github.com/dart-lang/sdk/commit/7054159b904fe35ac5b5a30426729821085aea35

[Anders Johnsen, 2015-07-09 07:11:23]

ajohnsen@google.com changed reviewers:
+ floitsch@google.com, kasperl@google.com

[floitsch, 2015-07-09 08:54:18]

LGTM.

[Anders Johnsen, 2015-07-09 11:41:12]

Committed patchset #1 (id:1) manually as
7054159b904fe35ac5b5a30426729821085aea35 (presubmit successful).

[Siggi Cherem (dart-lang), 2015-07-09 20:03:13]

sigmund@google.com changed reviewers:
+ sigmund@google.com

[Siggi Cherem (dart-lang), 2015-07-09 20:03:13]

what's preventing us from using async/await?

[floitsch, 2015-07-10 09:37:54]

On 2015/07/09 20:03:13, Siggi Cherem (dart-lang) wrote:
> what's preventing us from using async/await?

Fletch doesn't support it yet.

[Siggi Cherem (dart-lang), 2015-07-10 17:21:58]

On 2015/07/10 09:37:54, floitsch wrote:
> On 2015/07/09 20:03:13, Siggi Cherem (dart-lang) wrote:
> > what's preventing us from using async/await?
> 
> Fletch doesn't support it yet.

Are there other features like this that it doesn't support? I was planning on
start using null-aware operators any time now.

I'm surprised fletch is adding constraints on what we can do in dart2js though.
I know fletch uses dart2js to build bytecodes, but I thought it would simply run
dart2js on the vm, not directly in fletch itself. Is there an actual need to run
the compiler within fletch?

Honestly, I really would like us to be able to use the dart language features
freely in dart2js. So I'd like to chat about how we get there quickly.

[floitsch, 2015-07-10 17:28:37]

On 2015/07/10 17:21:58, Siggi Cherem (dart-lang) wrote:
> On 2015/07/10 09:37:54, floitsch wrote:
> > On 2015/07/09 20:03:13, Siggi Cherem (dart-lang) wrote:
> > > what's preventing us from using async/await?
> > 
> > Fletch doesn't support it yet.
> 
> Are there other features like this that it doesn't support? I was planning on
> start using null-aware operators any time now.
Go ahead. If there are features that are missing in Fletch, then they should be
added to Fletch.
Async/await is a completely different story, because it is so difficult to add
to a VM (just look at how long it took the VM and dart2js to add it).
Since dart2js only uses async/await in extremely few cases, it doesn't make
sense to hold Fletch back just for that.

> 
> I'm surprised fletch is adding constraints on what we can do in dart2js
though.
> I know fletch uses dart2js to build bytecodes, but I thought it would simply
run
> dart2js on the vm, not directly in fletch itself. Is there an actual need to
run
> the compiler within fletch?
Fletch is now able to self-host. That's a very nice result.

> 
> Honestly, I really would like us to be able to use the dart language features
> freely in dart2js. So I'd like to chat about how we get there quickly.
If I had the impression that this would impact the work on dart2js I wouldn't
have LGTMed the CL.