PPC: VectorICs: refactoring to eliminate "for queries only" vector ic mode.

PPC: VectorICs: refactoring to eliminate "for queries only" vector ic mode.

Port 1a5751f9b3ca682fadb6fce8202dda2db5b017c6

Original commit message:
    Since we need the notion of a dummy vector ic, we can use that to avoid
    a special case of the IC constructor. Also, consolidate the two dummy
    ICs into one.

R=mvstanton@chromium.org, michael_dawson@ca.ibm.com, jyan@ca.ibm.com, joransiu@ca.ibm.com
BUG=

Committed: https://crrev.com/de7e8a8c6df64b4db4f4f9d472d5db3aee497b70
Cr-Commit-Position: refs/heads/master@{#29959}

[JoranSiu, 2015-07-31 19:00:00]

lgtm

[MTBrandyberry, 2015-07-31 19:03:07]

The CQ bit was checked by mbrandy@us.ibm.com

[commit-bot: I haz the power, 2015-07-31 19:03:21]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1261433007/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1261433007/1

[commit-bot: I haz the power, 2015-07-31 19:26:43]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-07-31 19:27:13]

Patchset 1 (id:??) landed as
https://crrev.com/de7e8a8c6df64b4db4f4f9d472d5db3aee497b70
Cr-Commit-Position: refs/heads/master@{#29959}

[john.yan, 2015-07-31 20:29:32]

lgtm