[cq] Add mips compile trybots.

NOTRY=true

Review URL: https://codereview.chromium.org/1051093004

Cr-Commit-Position: refs/heads/master@{#27820}

PRESUBMIT.py

@@ -256,6 +256,8 @@ def GetPreferredTryMasters(project, change):
       'v8_mac_rel': set(['defaulttests']),
       'v8_linux_arm_rel': set(['defaulttests']),
       'v8_linux_arm64_rel': set(['defaulttests']),
+      'v8_linux_mipsel_compile_rel': set(['defaulttests']),
+      'v8_linux_mips64el_compile_rel': set(['defaulttests']),
       'v8_android_arm_compile_rel': set(['defaulttests']),
       'v8_linux_chromium_gn_rel': set(['defaulttests']),
     },

testing/commit_queue/config.json

@@ -47,6 +47,12 @@
                     "v8_linux_gcc_compile_rel": [
                         "defaulttests"
                     ],
+                    "v8_linux_mipsel_compile_rel": [
+                        "defaulttests"
+                    ],
+                    "v8_linux_mips64el_compile_rel": [
+                        "defaulttests"
+                    ],
                     "v8_linux_nodcheck_rel": [
                         "defaulttests"
                     ],