Correctly setup the freelist of the coderange on Win64

Correctly setup the freelist of the coderange on Win64

Since we have a special guard page at the beginning of the code range on
win64, we need to make sure to adjust the size of the free list
accordingly when creating it.

BUG=chromium:447555
R=hpayer@chromium.org
LOG=y

Committed: https://crrev.com/21ce2464232e6496408bb90a291a0fbd87b1baf7
Cr-Commit-Position: refs/heads/master@{#26012}

[Hannes Payer (out of office), 2015-01-09 12:45:43]

lgtm

[jochen (gone - plz use gerrit), 2015-01-09 12:47:13]

The CQ bit was checked by jochen@chromium.org

[commit-bot: I haz the power, 2015-01-09 12:48:11]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/843973002/20001

[commit-bot: I haz the power, 2015-01-09 13:07:34]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-01-09 13:07:52]

Patchset 2 (id:??) landed as
https://crrev.com/21ce2464232e6496408bb90a291a0fbd87b1baf7
Cr-Commit-Position: refs/heads/master@{#26012}