* Use documentation comments from inherited properties when @inheritDoc is present
The JSDoc `@ineheritDoc` [tag](http://usejsdoc.org/tags-inheritdoc.html)
"indicates that a symbol should inherit its documentation from its
parent class". In the case of a TypeScript file, this also includes
implemented interfaces and parent interfaces.
With this change, a class method or property (or an interface property)
with the `@inheritDoc` tag in its JSDoc comment will automatically use
the comments from its nearest ancestor that has no `@inheritDoc` tag.
To prevent breaking backwards compatibility,
`Symbol.getDocumentationComment` now accepts an optional `TypeChecker`
instance to support this feature.
fixes#8912
* Use ts.getJSDocTags as per @andy-ms 's recommendation
* Convert @inheritDoc tests to verify.quickInfoAt
* Concatenate inherited and local docs when @inheritDoc is present
* Make typeChecker param explicitly `TypeChecker | undefined`
* Re-accept baseline after switch to explicit `| undefined`
* Update APISample_jsodc.ts to match new getDocumentationComment signature
* Re-accept baselines after rebasing
i.e. use "var v: string" instead of "(var) v: string".
The parens case should only be used when we're using an english description instead of
an actual language construct.
