[stdlib] Implement the new _modify accessor in Dictionary.subscript#18974

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swift-ci merged 2 commits intoswiftlang:masterfrom

lorentey:dictionary-generalized-accessors

Sep 10, 2018

Commits on Aug 25, 2018

[stdlib] Implement the new _modify accessor in Dictionary.subscript
lorentey
committed

Commits on Aug 26, 2018

[stdlib] Fix crucial thinko
lorentey
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