'can not set method' error in wrong location.

[rakudrama]

f() => 1;

main() {
  f = null;
}

$ frogsh bug1a.dart
bug1a.dart:1:1: error: can not set method
f() => 1;
^^^^^^^^^
compilation failed with 1 errors

I would expect the error at the assignment.

For reference, the VM says:
'bug1a.dart': Error: line 4 pos 5: Left hand side of '=' is not assignable
  f = null;
    ^

[rakudrama]

Added Triaged label.

[DartBot]

This comment was originally written by jimhug@google.com

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Set owner to jimhug@google.com.
Added Started label.

[DartBot]

This comment was originally written by jimhug@google.com

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http://codereview.chromium.org/8536056/

Needs a test once testing infrastructure supports precise warning levels and line numbers.

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Added Fixed label.