MIPS: Major fixes and clean-up in asm. for instruction encoding.

MIPS: Major fixes and clean-up in asm. for instruction encoding.

- Fixed single float register type instruction en[de]coding in assembler and disassembler.
- Added max and min instructions for r6 and corresponding tests.
- Fixed selection instruction for boundary cases in simulator.
- Update assembler tests to be more thorough wrt boundary cases.

TEST=cctest/test-assembler-mips64/MIPS17, MIPS18
     cctest/test-disasm-mips64/Type1
     cctest/test-assembler-mips/MIPS16, MIPS17
     cctest/test-disasm-mips/Type1
BUG=

Committed: https://crrev.com/4b5af7b32ec97fd127b4bf9e2b3cb4ec6f0d3c2e
Cr-Commit-Position: refs/heads/master@{#27601}

[dusmil.imgtec, 2015-04-03 17:12:05]

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

[paul.l..., 2015-04-03 17:56:17]

Please fix the indicated DCHECK, then LGTM. Nice cleanup.

https://codereview.chromium.org/1057323002/diff/1/src/mips/assembler-mips.cc
File src/mips/assembler-mips.cc (right):

https://codereview.chromium.org/1057323002/diff/1/src/mips/assembler-mips.cc#...
src/mips/assembler-mips.cc:1925: DCHECK(kArchVariant == kMips64r6);
Should be kMips32r6 here.

https://codereview.chromium.org/1057323002/diff/1/src/mips64/simulator-mips64.cc
File src/mips64/simulator-mips64.cc (right):

https://codereview.chromium.org/1057323002/diff/1/src/mips64/simulator-mips64...
src/mips64/simulator-mips64.cc:2924: const int32_t fd_reg = instr->FdValue();
tiny nit of a nit: you changed the pretty alignment here .....

[dusmil.imgtec, 2015-04-06 11:02:56]

Done. Thanks for catching these.

[dusmil.imgtec, 2015-04-06 11:05:59]

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

[dusmil.imgtec, 2015-04-06 11:05:59]

The patchset sent to the CQ was uploaded after l-g-t-m from paul.lind@imgtec.com
Link to the patchset: https://codereview.chromium.org/1057323002/#ps10001
(title: "Typos addressed.")

[commit-bot: I haz the power, 2015-04-06 11:06:10]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1057323002/10001

[commit-bot: I haz the power, 2015-04-06 11:54:45]

Committed patchset #2 (id:10001)

[commit-bot: I haz the power, 2015-04-06 11:54:55]

Patchset 2 (id:??) landed as
https://crrev.com/4b5af7b32ec97fd127b4bf9e2b3cb4ec6f0d3c2e
Cr-Commit-Position: refs/heads/master@{#27601}