MIPS64: Improve loading constants for double and integer values.

MIPS64: Improve loading constants for double and integer values.

This CL reduces the size of generated code for snapshot by 1.6%.

TEST=
BUG=

Committed: https://crrev.com/e6459674bb0c655e3d1a9fb410a0bd24919e5b93
Cr-Commit-Position: refs/heads/master@{#27514}

[dusmil.imgtec, 2015-03-27 16:33:12]

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

[dusmil.imgtec, 2015-03-27 16:33:13]

PTAL.

[paul.l..., 2015-03-27 17:50:58]

LGTM.

[Benedikt Meurer, 2015-03-27 18:23:51]

Nice. LGTM

[dusmil.imgtec, 2015-03-30 10:09:53]

The CQ bit was checked by dusan.milosavljevic@imgtec.com

[commit-bot: I haz the power, 2015-03-30 10:10:04]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1039283002/1

[commit-bot: I haz the power, 2015-03-30 10:32:21]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-03-30 10:32:33]

Patchset 1 (id:??) landed as
https://crrev.com/e6459674bb0c655e3d1a9fb410a0bd24919e5b93
Cr-Commit-Position: refs/heads/master@{#27514}