Print properly signed displacement in disassembler.

Print properly signed displacement in disassembler.

R=titzer@chromium.org
BUG=

Committed: https://code.google.com/p/v8/source/detail?r=19667

[Michael Starzinger, 2014-03-04 18:29:03]

This is a followup to https://codereview.chromium.org/176993004/ which fixes
printing for all operand types, ports it to x64 and adds unit test cases.

Oh and here is a crazy idea, we could, I don't know, maybe actually compile and
run the cctest/test-disasm-x64 test case.

[titzer, 2014-03-05 08:43:08]

lgtm

[Michael Starzinger, 2014-03-05 09:28:35]

Committed patchset #2 manually as r19667 (tree was closed).