Change and simplify RelocInfo format.

Change and simplify RelocInfo format.
 - we now have 6 bits to store RelocInfo mode.
 - removed a redundant tag byte per long reloc info entry.
 - renamed methods to be more precise.

Committed: https://crrev.com/9d9256cc795135d3603acc97940e8876e8816c45
Cr-Commit-Position: refs/heads/master@{#29573}

[Yang, 2015-07-10 10:11:59]

yangguo@chromium.org changed reviewers:
+ mstarzinger@chromium.org

[Yang, 2015-07-10 10:12:00]

Please take a look.

The motivation for this change is so that we can add more reloc info modes.

Which is so that we can add a reloc info mode for generator continuations.

Which is so that we can translate non-debug full code PC into debug full code PC
for suspended generators based on reloc info for calls and generator
continuations.

Which is to fix crbug.com/507070 by having a more robust PC translation
mechanism.

[Michael Starzinger, 2015-07-10 11:22:37]

LGTM.

https://codereview.chromium.org/1230183002/diff/1/src/assembler.cc
File src/assembler.cc (left):

https://codereview.chromium.org/1230183002/diff/1/src/assembler.cc#oldcode287
src/assembler.cc:287: //          pc-jump (variable length):
Should we preserve the description of the variable length encoding? It's still
used for PC_JUMP, correct?

https://codereview.chromium.org/1230183002/diff/1/src/assembler.cc
File src/assembler.cc (right):

https://codereview.chromium.org/1230183002/diff/1/src/assembler.cc#newcode761
src/assembler.cc:761: case PC_JUMP:
Should this really be inreachable?

https://codereview.chromium.org/1230183002/diff/1/src/assembler.cc#newcode864
src/assembler.cc:864: case PC_JUMP:
Likewise.

https://codereview.chromium.org/1230183002/diff/1/src/assembler.h
File src/assembler.h (right):

https://codereview.chromium.org/1230183002/diff/1/src/assembler.h#newcode352
src/assembler.h:352: // The minimum size of a comment is equal to three bytes
for the extra tagged
nit: s/three/two/

[Yang, 2015-07-10 11:42:38]

The CQ bit was checked by yangguo@chromium.org

[Yang, 2015-07-10 11:42:38]

The patchset sent to the CQ was uploaded after l-g-t-m from
mstarzinger@chromium.org
Link to the patchset: https://codereview.chromium.org/1230183002/#ps20001
(title: "addressed comments")

[commit-bot: I haz the power, 2015-07-10 11:42:48]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1230183002/20001

[commit-bot: I haz the power, 2015-07-10 12:00:50]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-07-10 12:00:51]

Try jobs failed on following builders:
  v8_linux64_avx2_rel on tryserver.v8 (JOB_FAILED,
http://build.chromium.org/p/tryserver.v8/builders/v8_linux64_avx2_rel/builds/...)

[Yang, 2015-07-10 12:49:16]

fix typo

[Yang, 2015-07-10 12:49:22]

The CQ bit was checked by yangguo@chromium.org

[Yang, 2015-07-10 12:49:22]

The patchset sent to the CQ was uploaded after l-g-t-m from
mstarzinger@chromium.org
Link to the patchset: https://codereview.chromium.org/1230183002/#ps40001
(title: "fix typo")

[commit-bot: I haz the power, 2015-07-10 12:49:35]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1230183002/40001

[commit-bot: I haz the power, 2015-07-10 13:14:41]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2015-07-10 13:14:59]

Patchset 3 (id:??) landed as
https://crrev.com/9d9256cc795135d3603acc97940e8876e8816c45
Cr-Commit-Position: refs/heads/master@{#29573}