Fix issue with --print-ast and class expressions

Fix issue with --print-ast and class expressions

Make sure that --print-ast works even when the class expression has no
name.

This also updates the printer to print the properties of the class
literal.

BUG=v8:4138
LOG=N
R=rossberg

Review URL: https://codereview.chromium.org/1165613003

Cr-Commit-Position: refs/heads/master@{#28728}