Add MIPS SIMD Arch (MSA) optimized MirrorRow function

BUILD.gn

 # Copyright 2014 The LibYuv Project Authors. All rights reserved.
 #
 # Use of this source code is governed by a BSD-style license
 # that can be found in the LICENSE file in the root of the source
 # tree. An additional intellectual property rights grant can be found
 # in the file PATENTS. All contributing project authors may
 # be found in the AUTHORS file in the root of the source tree.
 
 import("libyuv.gni")
 import("//testing/test.gni")
@@ skipping 76 matching lines @@
 
   if (!is_ios) {
     defines += [ "HAVE_JPEG" ]
     deps += [ "//third_party:jpeg" ]
   }
 
   if (libyuv_use_neon) {
     deps += [ ":libyuv_neon" ]
   }
 
+  if (libyuv_use_msa) {
+    deps += [ ":libyuv_msa" ]
+  }
+
   if (is_nacl) {
     # Always enable optimization under NaCl to workaround crbug.com/538243 .
     configs -= [ "//build/config/compiler:default_optimization" ]
     configs += [ "//build/config/compiler:optimize_max" ]
   }
 }
 
 if (libyuv_use_neon) {
   static_library("libyuv_neon") {
     sources = [
@@ skipping 10 matching lines @@
 
     public_configs = [ ":libyuv_config" ]
 
     if (current_cpu != "arm64") {
       configs -= [ "//build/config/compiler:compiler_arm_fpu" ]
       cflags = [ "-mfpu=neon" ]
     }
   }
 }
 
+if (libyuv_use_msa) {
+  static_library("libyuv_msa") {
+    sources = [
+      # MSA Source Files
+      "source/row_msa.cc",
+    ]
+
+    public_configs = [ ":libyuv_config" ]
+  }
+}
+
 if (libyuv_include_tests) {
   config("libyuv_unittest_warnings_config") {
     if (!is_win) {
       cflags = [
         # TODO(fbarchard): Fix sign and unused variable warnings.
         "-Wno-sign-compare",
         "-Wno-unused-variable"
       ]
     }
     if (is_win) {
@@ skipping 112 matching lines @@
   }
 
   executable("cpuid") {
     sources = [
       # sources
       "util/cpuid.c"
     ]
     deps = [ ":libyuv" ]
   }
 }