This reverts commit 3e0bf580.

Reason for revert: MSVC does not compile any more, see https://build.chromium.org/p/client.v8/builders/V8%20Win64%20-%20msvc/builds/172

Original change's description:
> MIPS[64] Implementation of MSA instructions in builtin simulator
> 
> This commit is a step toward enabling test-run-wasm-simd tests for MIPS.
> 36 of those were failing in V8 builtin simulator because some instructions
> were not implemented.  Also there are minor fixes to some of the already
> implemented instructions.
> 
> This commit has only 32-bit implementation. After review I will add
> 64-bit version.
> 
> Bug: 
> Change-Id: I25b0cac352db3efb56b922ace64ab2aaef82472d
> Reviewed-on: https://chromium-review.googlesource.com/744008
> Reviewed-by: Ivica Bogosavljevic <ivica.bogosavljevic@mips.com>
> Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
> Commit-Queue: Ivica Bogosavljevic <ivica.bogosavljevic@mips.com>
> Cr-Commit-Position: refs/heads/master@{#49439}

TBR=jkummerow@chromium.org,mstarzinger@chromium.org,mlippautz@chromium.org,bmeurer@chromium.org,predrag.rudic@mips.com,ivica.bogosavljevic@mips.com,Ilija.Pavlovic@mips.com,sreten.kovacevic@mips.com,Miran.Karic@imgtec.com

Change-Id: Ic0c6339473481fa75908e942bc86de2b5c6349d8
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/776655Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#49441}