Add support for building v8 on mips and mips64 using GN.

build/toolchain/linux/BUILD.gn

 # Copyright 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import("//build/config/sysroot.gni")
 import("//build/toolchain/gcc_toolchain.gni")
 
 clang_toolchain("clang_arm") {
   toolprefix = "arm-linux-gnueabihf-"
   toolchain_args = {
@@ skipping 65 matching lines @@
 }
 
 clang_toolchain("clang_x86_v8_mipsel") {
   toolchain_args = {
     current_cpu = "x86"
     v8_current_cpu = "mipsel"
     current_os = "linux"
   }
 }
 
+clang_toolchain("clang_x86_v8_mips") {
+  toolchain_args = {
+    current_cpu = "x86"
+    v8_current_cpu = "mips"
+    current_os = "linux"
+  }
+}
+
 gcc_toolchain("x86") {
   cc = "gcc"
   cxx = "g++"
 
   readelf = "readelf"
   nm = "nm"
   ar = "ar"
   ld = cxx
 
   # Output linker map files for binary size analysis.
@@ skipping 25 matching lines @@
 }
 
 clang_toolchain("clang_x64_v8_mips64el") {
   toolchain_args = {
     current_cpu = "x64"
     v8_current_cpu = "mips64el"
     current_os = "linux"
   }
 }
 
+clang_toolchain("clang_x64_v8_mips64") {
+  toolchain_args = {
+    current_cpu = "x64"
+    v8_current_cpu = "mips64"
+    current_os = "linux"
+  }
+}
+
 gcc_toolchain("x64") {
   cc = "gcc"
   cxx = "g++"
 
   readelf = "readelf"
   nm = "nm"
   ar = "ar"
   ld = cxx
 
   # Output linker map files for binary size analysis.
@@ skipping 54 matching lines @@
   nm = "nm"
   ar = "ar"
   ld = cxx
 
   toolchain_args = {
     current_cpu = "ppc64"
     current_os = "linux"
     is_clang = false
   }
 }
+
+gcc_toolchain("mips") {
+  cc = "gcc"
+  cxx = "g++"
+
+  readelf = "readelf"
+  nm = "nm"
+  ar = "ar"
+  ld = cxx
+
+  toolchain_args = {
+    current_cpu = "mips"
+    current_os = "linux"
+    is_clang = false
+  }
+}
+
+gcc_toolchain("mips64") {
+  cc = "gcc"
+  cxx = "g++"
+
+  readelf = "readelf"
+  nm = "nm"
+  ar = "ar"
+  ld = cxx
+
+  toolchain_args = {
+    current_cpu = "mips64"
+    current_os = "linux"
+    is_clang = false
+  }
+}