Error.stack contains function.name if its type is string.
Otherwise if function have inferred name then .stack contains it.
For functions from eval .stack property contains "eval".

LOG=N
BUG=chromium:17356
R=yurys@chromium.org

Review URL: https://codereview.chromium.org/919653002

Cr-Commit-Position: refs/heads/master@{#27186}