Special printing for type feedback vectors.

Special printing for type feedback vectors.

Gdb macro jfv on an object will print it as a feedback vector.
Printouts look like this:

DebugPrint: 0x5dc0d2ad: [TypeFeedbackVector]
 - length: 12
 - ics with type info: 3
 - generic ics: 0
 ICSlot 0 CALL_IC MONOMORPHIC
  [4]: 0x5dc0d365 WeakCell for 0x5dc0cd69 <JS Function foo (SharedFunctionInfo 0x5dc0cb0d)>
  [5]: 0x4203c4c1 <Code: HANDLER>
 ICSlot 1 LOAD_IC MONOMORPHIC
  [6]: 0x5dc0d1f5 WeakCell for 0x3a710481 <Map(FAST_HOLEY_SMI_ELEMENTS)>
  [7]: 0x4203a1c1 <Code: HANDLER>
 ICSlot 2 LOAD_IC UNINITIALIZED
  [8]: 0x3060d045 <Symbol: 711234650 <String[20]: uninitialized_symbol>>
  [9]: 0x3060d045 <Symbol: 711234650 <String[20]: uninitialized_symbol>>
 ICSlot 3 LOAD_IC MONOMORPHIC
  [10]: 0x5dc0d3b5 WeakCell for 0x3a710d71 <Map(FAST_HOLEY_ELEMENTS)>
  [11]: 0x4202af01 <Code: HANDLER>

BUG=

Committed: https://crrev.com/9386b861fda66cd36125c36ab63909784cc409db
Cr-Commit-Position: refs/heads/master@{#29679}

[mvstanton, 2015-07-15 10:48:30]

mvstanton@chromium.org changed reviewers:
+ bmeurer@chromium.org

[mvstanton, 2015-07-15 10:49:39]

Hi Benedikt,
Here is the printing function we discussed a little while ago.

[Benedikt Meurer, 2015-07-15 11:03:40]

Nice. LGTM!

[mvstanton, 2015-07-15 11:53:40]

The CQ bit was checked by mvstanton@chromium.org

[commit-bot: I haz the power, 2015-07-15 11:53:53]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1225403005/1

[commit-bot: I haz the power, 2015-07-15 12:22:01]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-07-15 12:22:10]

Patchset 1 (id:??) landed as
https://crrev.com/9386b861fda66cd36125c36ab63909784cc409db
Cr-Commit-Position: refs/heads/master@{#29679}