[refactor] js_codegen: remove currentClass, simplify visitSimpleIdentifier

[refactor] js_codegen: remove currentClass, simplify visitSimpleIdentifier

We were tracking currentClass for no real reason.

Also attempted to discern what visitSimpleIdentifier was actually doing. It now prefers the original element (the "field" not the synthetic getter/setter) whenever possible. Previously was a mismash.

This little change tripped on the (larger, not fixed yet) issue #138 ... but I think I found a way around the issue for now, by tweaking the private TypeDataArray class.

R=jacobr@google.com

Committed: https://github.com/dart-lang/dev_compiler/commit/23fb9a7823b28e5371b5a4b30a1e786df54ae3f3

[Jennifer Messerly, 2015-04-16 22:46:41]

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

[Jennifer Messerly, 2015-04-16 22:50:30]

https://codereview.chromium.org/1095563003/diff/1/lib/runtime/dart/_native_ty...
File lib/runtime/dart/_native_typed_data.js (left):

https://codereview.chromium.org/1095563003/diff/1/lib/runtime/dart/_native_ty...
lib/runtime/dart/_native_typed_data.js:586: return dart.as(this.length,
core.int);
this would've overflowed the stack

https://codereview.chromium.org/1095563003/diff/1/lib/src/codegen/js_codegen....
File lib/src/codegen/js_codegen.dart (left):

https://codereview.chromium.org/1095563003/diff/1/lib/src/codegen/js_codegen....
lib/src/codegen/js_codegen.dart:998: var variable = e is PropertyAccessorElement
? e.variable : e;
"variable" was misleading ... this is just the "real" original declaring
element. We ignore the less useful PropertyAccess (strangely they aren't
ClassMemberElements)

https://codereview.chromium.org/1095563003/diff/1/lib/src/codegen/js_codegen....
File lib/src/codegen/js_codegen.dart (right):

https://codereview.chromium.org/1095563003/diff/1/lib/src/codegen/js_codegen....
lib/src/codegen/js_codegen.dart:997: if (element is PropertyAccessorElement)
element = accessor.variable;
after this point we always use `element`.

[Jennifer Messerly, 2015-04-21 16:26:43]

friendly ping. This one shouldn't be too bad :)

[Jacob, 2015-04-21 17:46:03]

lgtm

[Jennifer Messerly, 2015-04-21 18:21:24]

Committed patchset #1 (id:1) manually as
23fb9a7823b28e5371b5a4b30a1e786df54ae3f3 (presubmit successful).