Leading whitespaces are used to indiate control depth,
opcode prefix should be printed after the whitespaces.

Change-Id: I0a22864d1d5a2e643b15a4c10909c0387922f8e3
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2224959Reviewed-by: Clemens Backes <clemensb@chromium.org>
Commit-Queue: Jie Pan <jie.pan@intel.com>
Cr-Commit-Position: refs/heads/master@{#68092}