small refactor to move JsPeer code out of _finishClassDef

small refactor to move JsPeer code out of _finishClassDef

Nothing wrong with it there, but it was tangled up with the _emitClassIfNeeded code I'm trying to fix for use-before-define issues. Also _finishClassDef's reason for existing is shared code between FunctionTypeAlias/ClassTypeAlias/ClassDeclaration, so the fact that only one of those cares about jsPeer was a sign.

(My first thought was actually _finishClassMembers, but discovered the generics issue: https://github.com/dart-lang/dev_compiler/issues/154)

R=jacobr@google.com

Committed: https://github.com/dart-lang/dev_compiler/commit/7fc439ae08e39884e8c9410e95e0006a6f8ab5cf

[Jennifer Messerly, 2015-04-23 17:03:31]

jmesserly@google.com changed reviewers:
+ jacobr@google.com

[Jennifer Messerly, 2015-04-23 17:05:43]

https://codereview.chromium.org/1061543004/diff/1/lib/src/codegen/js_codegen....
File lib/src/codegen/js_codegen.dart (right):

https://codereview.chromium.org/1061543004/diff/1/lib/src/codegen/js_codegen....
lib/src/codegen/js_codegen.dart:354:
'dart.copyProperties(dart.global.#.prototype, #.prototype);', [
hmmm, it occurs to me we should assert !_lazyClass if we reach this point, as
this will cause the type name to be evaluated eagerly.

[Jacob, 2015-04-23 17:09:14]

lgtm

https://codereview.chromium.org/1061543004/diff/1/lib/src/codegen/js_codegen....
File lib/src/codegen/js_codegen.dart (right):

https://codereview.chromium.org/1061543004/diff/1/lib/src/codegen/js_codegen....
lib/src/codegen/js_codegen.dart:354:
'dart.copyProperties(dart.global.#.prototype, #.prototype);', [
On 2015/04/23 17:05:43, John Messerly wrote:
> hmmm, it occurs to me we should assert !_lazyClass if we reach this point, as
> this will cause the type name to be evaluated eagerly.

make it so.

[Jennifer Messerly, 2015-04-23 17:16:13]

Thanks! adding the assert with this comment:

        // This class isn't allowed to be lazy, because we need to set up
        // the native JS type eagerly at this point.
        // If we wanted to support laziness, we could defer the hookup until
        // the end of the Dart library cycle load.
        assert(!_lazyClass(type));

[Jennifer Messerly, 2015-04-23 17:17:17]

Committed patchset #1 (id:1) manually as
7fc439ae08e39884e8c9410e95e0006a6f8ab5cf (presubmit successful).