Suppress unnamed library analyzer spam in shelldb

Revert "Add library names to many sky libraries"

This reverts commit 1337e0a803a54ee92d6dce7f8c4a6335f7cbb9fa.

BUG=
R=abarth@chromium.org

Review URL: https://codereview.chromium.org/1142893007

engine/src/flutter/tools/shelldb

@@ -47,6 +47,9 @@ _IGNORED_PATTERNS = [
   re.compile(r'^\[error\] Native functions can only be declared in'),
   # TODO: Remove this once dev SDK includes Uri.directory constructor.
   re.compile(r'.*The class \'Uri\' does not have a constructor \'directory\''),
+  # TODO: Remove this once Sky no longer generates this warning.
+  # dartbug.com/22836
+  re.compile(r'.*cannot both be unnamed'),
 ]
 
 # This 'strict dictionary' approach is useful for catching typos.