MIPS: Introduce LanguageMode, drop StrictMode.

MIPS: Introduce LanguageMode, drop StrictMode.

Port c7851da4aefb644ab198ead1fa284932fd424797

Original commit message:
This enables adding more language modes in the future.

For maximum flexibility, LanguageMode is a bitmask, so we're not restricted to
use a sequence of language modes which are progressively stricter, but we can
express the language mode as combination of features.

For now, LanguageMode can only be "sloppy" or "strict", and there are
STATIC_ASSERTS in places which need to change when more modes are added.

LanguageMode is a bit like the old LanguageMode when "extended" mode was still
around (see https://codereview.chromium.org/8417035 and
https://codereview.chromium.org/181543002 ) except that it's transmitted through
all the layers (there's no StrictModeFlag).

BUG=

Committed: https://crrev.com/ff0c70380a47ab803518ce31febaf99e32a26e8e
Cr-Commit-Position: refs/heads/master@{#26431}

[balazs.kilvady, 2015-02-04 13:38:06]

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

[marja, 2015-02-04 13:41:38]

lgtm

[balazs.kilvady, 2015-02-04 13:45:05]

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

[commit-bot: I haz the power, 2015-02-04 13:45:48]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/890413003/1

[commit-bot: I haz the power, 2015-02-04 15:14:46]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-02-04 15:15:01]

Patchset 1 (id:??) landed as
https://crrev.com/ff0c70380a47ab803518ce31febaf99e32a26e8e
Cr-Commit-Position: refs/heads/master@{#26431}