[MIPS] Use gold as default linker for Linux

Start using bundled gold as default linker for Linux MIPS,
since gold in current bundled binutils (2.26) supports mips32.

BUG=none
TEST=Build Chromium for Linux MIPS

Review-Url: https://codereview.chromium.org/2027173002
Cr-Commit-Position: refs/heads/master@{#397246}

build/common.gypi

@@ -902,7 +902,7 @@
         # are using a custom toolchain and need to control -B in ldflags.
         # Do not use 32-bit gold on 32-bit hosts as it runs out address space
         # for component=static_library builds.
-        ['(OS=="linux" or OS=="android") and (target_arch=="x64" or target_arch=="arm" or (target_arch=="ia32" and host_arch=="x64"))', {
+        ['(OS=="linux" or OS=="android") and (target_arch=="x64" or target_arch=="arm" or target_arch=="mipsel" or (target_arch=="ia32" and host_arch=="x64"))', {
           'linux_use_bundled_gold%': 1,
         }, {
           'linux_use_bundled_gold%': 0,

build/config/compiler/compiler.gni

@@ -39,7 +39,7 @@ declare_args() {
   use_gold = !use_lld && !(is_chromecast && is_linux &&
                            (current_cpu == "arm" || current_cpu == "mipsel")) &&
              ((is_linux && (current_cpu == "x64" || current_cpu == "x86" ||
-                            current_cpu == "arm")) ||
+                            current_cpu == "arm" || current_cpu == "mipsel")) ||
               (is_android && (current_cpu == "x86" || current_cpu == "x64" ||
                               current_cpu == "arm")))
 }