JsChecker may not honor function level suppressions

When [updating](https://github.com/bazelbuild/rules_closure/pull/71) to library/compiler version v20160517 JsChecker reports the following warnings:

```
INFO: From Checking 812 JS files in //closure/library:library:
external/closure_library/closure/goog/datasource/expr.js:276: WARNING lintChecks JSC_MISSING_REQUIRE_CALL_WARNING - missing require: 'goog.ds.DataManager'
goog.ds.DataManager.getInstance();
^

external/closure_library/closure/goog/graphics/vmlelement.js:116: WARNING lintChecks JSC_MISSING_REQUIRE_CALL_WARNING - missing require: 'goog.graphics.VmlGraphics'
goog.graphics.VmlGraphics.toSizeCoord(height);
^

external/closure_library/closure/goog/graphics/vmlelement.js:276: WARNING lintChecks JSC_MISSING_REQUIRE_CALL_WARNING - missing require: 'goog.graphics.VmlGraphics'
style.height = goog.graphics.VmlGraphics.toSizePx(height);
^

external/closure_library/closure/goog/graphics/vmlelement.js:421: WARNING lintChecks JSC_MISSING_REQUIRE_CALL_WARNING - missing require: 'goog.graphics.VmlGraphics'
style.height = goog.graphics.VmlGraphics.toPosPx(height);
^

external/closure_library/closure/goog/net/browsertestchannel.js:376: WARNING lintChecks JSC_MISSING_REQUIRE_CALL_WARNING - missing require: 'goog.net.BrowserChannel'
goog.net.BrowserChannel.createChannelRequest(this, this.channelDebug_);
^

external/closure_library/closure/goog/net/channelrequest.js:1129: WARNING lintChecks JSC_MISSING_REQUIRE_CALL_WARNING - missing require: 'goog.net.BrowserChannel'
this.watchDogTimerId_ = goog.net.BrowserChannel.setTimeout(
^

0 error(s), 6 warning(s)
```

However, each of these functions already contains a function level suppression:

[closure/goog/datasource/expr.js](https://github.com/google/closure-library/blob/master/closure/goog/datasource/expr.js#L267)
[closure/goog/graphics/vmlelement.js](https://github.com/google/closure-library/blob/master/closure/goog/graphics/vmlelement.js#L106)
[closure/goog/net/browsertestchannel.js](https://github.com/google/closure-library/blob/master/closure/goog/net/browsertestchannel.js#L349)
[closure/goog/net/channelrequest.js](https://github.com/google/closure-library/blob/master/closure/goog/net/channelrequest.js#L1122)

More research should be done to understand what is going on here. It could be possible that JSChecker is not honoring suppressions on function bodies.