Doc comment applied to all components of dotted namespace declaration

TypeScript Version: 2.1.5, 2.2-rc

Code

/** Performance measurements for the compiler. */
namespace ts.performance {}

Expected behavior:
The doc comment should show up in quickinfo/completion for references to the innermost declared namespace performance, but not for ts.

Actual behavior:
The doc comment appears in quickinfo/completion for references to both performance and ts, even though for the outer namespace ts it's most likely irrelevant:

首先使用 TypeScript 2.1.5 或 2.2-rc 重現點號命名空間範例，然後追蹤外層和最內層命名空間參照的 quickinfo 和 completion 進入點。完成標準是：在 quickinfo 和 completion 中，註解會出現在 performance 上，但不會出現在 ts 上。