Revert of AVX 2 SrcOver blits: color32, blitmask. (patchset #24 id:450001 of https://codereview.chromium.org/1532613002/ )

Reason for revert:
Bot failures

Original issue's description:
> AVX 2 SrcOver blits: color32, blitmask.
>
> As a follow up to the SSE 4.1 CL, this should look pretty familiar.
>
> I've made some organizational changes around how we load, store, pack, and unpack data that I think makes things clearer and more orthogonal, and it'll make it easier to try out a pmaddubsw lerp.  I have backported these changes to the SSE 4.1 code, and I hope that I can actually get a lot of this code templated for sharing between the two later.
>
> Perf changes (relative to SSE 4.1):
> Xfermode_SrcOver:      1650 -> 1180  (0.71x)  // large opaque blit
> Xfermode_SrcOver_aa:   1794 -> 1653  (0.92x)  // large opaque + small transparent
> text_16_AA_{FF,BK,WT}: 1.72 -> 1.59  (0.92x)  // small opaque blit
> text_16_AA_88:         1.83 -> 1.77  (0.97x)  // small transparent blit
>
> This should be a big throughout win, and a small latency win.
> This should all be pixel-exact to the previous SSE 4.1 code.
>
>
> GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1532613002
> CQ_EXTRA_TRYBOTS=client.skia:Test-Ubuntu-GCC-GCE-CPU-AVX2-x86_64-Release-SKNX_NO_SIMD-Trybot;client.skia.compile:Build-Ubuntu-GCC-x86_64-Release-CMake-Trybot,Build-Mac10.9-Clang-x86_64-Release-CMake-Trybot
>
> Committed: https://skia.googlesource.com/skia/+/5d2117015eb271e09faf4a7ddd89093c9d618a36

TBR=herb@google.com,mtklein@google.com,mtklein@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true

Review URL: https://codereview.chromium.org/1632713002
diff --git a/gyp/opts.gypi b/gyp/opts.gypi
index 1a0d030..f2d36b9 100644
--- a/gyp/opts.gypi
+++ b/gyp/opts.gypi
@@ -60,6 +60,6 @@
             '<(skia_src_path)/opts/SkOpts_avx.cpp',
         ],
         'avx2_sources': [
-            '<(skia_src_path)/opts/SkOpts_avx2.cpp',
+            '<(skia_src_path)/core/SkForceCPlusPlusLinking.cpp',
         ],
 }