Merge third_party/smhasher/src from https://chromium.googlesource.com/external/smhasher.git at 8adb1336422e3ad4d78ba54fb56692f2ed07124c

This commit was generated by merge_from_chromium.py.

Change-Id: I48bddcadccb4817edd8a80498e7f4d7ead9efeae
diff --git a/City.cpp b/City.cpp
index 4d70dd2..d7c33bc 100644
--- a/City.cpp
+++ b/City.cpp
@@ -351,7 +351,7 @@
   }
 }
 
-#ifdef __SSE4_2__
+#if defined(__SSE4_2__) && defined(__x86_64__)
 #include <nmmintrin.h>
 
 // Requires len >= 240.
diff --git a/City.h b/City.h
index fe2d3e2..c12c1bb 100644
--- a/City.h
+++ b/City.h
@@ -90,7 +90,7 @@
 
 // Conditionally include declarations for versions of City that require SSE4.2
 // instructions to be available.
-#ifdef __SSE4_2__
+#if defined(__SSE4_2__) && defined(__x86_64__)
 
 // Hash function for a byte array.
 uint128 CityHashCrc128(const char *s, size_t len);