Add loongson3a Build jobs.

Change-Id: I4a0259f82272099e08df0e7dea91489f6d641ca4
Reviewed-on: https://skia-review.googlesource.com/113670
Commit-Queue: Ben Wagner <benjaminwagner@google.com>
Reviewed-by: Mike Klein <mtklein@chromium.org>
diff --git a/gn/BUILD.gn b/gn/BUILD.gn
index e7fffa2..4c6eac2 100644
--- a/gn/BUILD.gn
+++ b/gn/BUILD.gn
@@ -112,6 +112,17 @@
       "-mfpu=neon",
       "-mthumb",
     ]
+  } else if (current_cpu == "loongson3a") {
+    asmflags += [ "-march=loongson3a" ]
+    cflags += [
+      "-march=loongson3a",
+
+      # Causes an internal compiler error.
+      "-DSKCMS_PORTABLE",
+    ]
+  } else if (current_cpu == "mips64el") {
+    asmflags += [ "-march=mips64" ]
+    cflags += [ "-march=mips64" ]
   } else if (current_cpu == "x86" && !is_win) {
     asmflags += [ "-m32" ]
     cflags += [