MIPS: ARM: Load undefined receiver sentinel without constant pool.

MIPS: ARM: Load undefined receiver sentinel without constant pool.

Port a820568b1ffbf76c3f80b9e00fc0b988b073dfaf

Each call to emit_32 uses 5 constant pool slots:
* the "emit_32" string
* undefined (the receiver)
* the argument (heap number)
* the load IC
* the call IC

This change cuts that down 20% to 4, by loading the undefined from the heap roots.

BUG=

Committed: https://crrev.com/c4b9d144e0db2df0165dd4e875a1cc0e5b63bcf5
Cr-Commit-Position: refs/heads/master@{#26995}

[balazs.kilvady, 2015-03-04 13:48:12]

balazs.kilvady@imgtec.com changed reviewers:
+ akos.palfi@imgtec.com, danno@chromium.org, dusan.milosavljevic@imgtec.com,
erikcorry@chromium.org, gergely.kis@imgtec.com, paul.lind@imgtec.com

[dusmil.imgtec, 2015-03-04 14:35:44]

lgtm.

[balazs.kilvady, 2015-03-04 16:25:19]

The CQ bit was checked by balazs.kilvady@imgtec.com

[commit-bot: I haz the power, 2015-03-04 16:26:19]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/963193005/1

[commit-bot: I haz the power, 2015-03-04 16:55:49]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-03-04 16:55:59]

Patchset 1 (id:??) landed as
https://crrev.com/c4b9d144e0db2df0165dd4e875a1cc0e5b63bcf5
Cr-Commit-Position: refs/heads/master@{#26995}