CallPrinter currently has only a single use, namely to print the call
site when throwing CalledNonCallable (ConstructedNonConstructable)
errors. This ensures that unicode call sites such as "あいう"() are
printed correctly by using an IncrementalStringBuilder internally.

BUG=637167

Review-Url: https://codereview.chromium.org/2265073002
Cr-Commit-Position: refs/heads/master@{#38790}