[analyzer] fix NodeReplacer for YieldStatement

fix NodeReplacer for YieldStatement
it was missing a return, so it always fell through to the visitNode error case

R=brianwilkerson@google.com

Committed: https://github.com/dart-lang/sdk/commit/fa5b8ce45607827d12532c9f78bb30c3273094a5

[Jennifer Messerly, 2015-06-25 17:38:18]

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

[Jennifer Messerly, 2015-06-25 17:38:19]

Verified with ./tools/test.py -m release pkg/analyzer, fails before the fix and
passes after.

https://codereview.chromium.org/1213503002/diff/1/pkg/analyzer/lib/src/genera...
File pkg/analyzer/lib/src/generated/ast.dart (right):

https://codereview.chromium.org/1213503002/diff/1/pkg/analyzer/lib/src/genera...
pkg/analyzer/lib/src/generated/ast.dart:13495: return true;
the other visit methods "return" after successful replace.
visitNode always throws:

throw new IllegalArgumentException(
        "The old node is not a child of it's parent");

[Brian Wilkerson, 2015-06-25 17:49:11]

LGTM. Thanks!

[Jennifer Messerly, 2015-06-25 17:59:26]

Committed patchset #1 (id:1) manually as
fa5b8ce45607827d12532c9f78bb30c3273094a5 (presubmit successful).