MIPS: Fix big-endian after r21774/r21803.

src/hydrogen-instructions.h

Index: src/hydrogen-instructions.h
diff --git a/src/hydrogen-instructions.h b/src/hydrogen-instructions.h
index f1720f444247d83635c84d00a99cf2457ee0022e..1b6168270847fd372d9ea49915ed23b7761c7673 100644
--- a/src/hydrogen-instructions.h
+++ b/src/hydrogen-instructions.h
@@ -6091,10 +6091,12 @@ class HObjectAccess V8_FINAL {
   }
 
   static HObjectAccess ForMapInstanceTypeAndBitField() {
-    STATIC_ASSERT((Map::kInstanceTypeOffset & 1) == 0);
-    STATIC_ASSERT(Map::kBitFieldOffset == Map::kInstanceTypeOffset + 1);
+    STATIC_ASSERT((Map::kInstanceTypeAndBitFieldOffset & 1) == 0);
+    // Ensure the two fields share one 16-bit word, endian-independent.
+    STATIC_ASSERT((Map::kBitFieldOffset & ~1) ==
+                  (Map::kInstanceTypeOffset & ~1));
     return HObjectAccess(kInobject,
-                         Map::kInstanceTypeOffset,
+                         Map::kInstanceTypeAndBitFieldOffset,
                          Representation::UInteger16());
   }