Adapt hash tests to big-endian systems.

The hash code, which has MurmurHash3 at its core, generates different
output depending on system endianness, so adapt the expected output on
big-endian systems.  MurmurHash3 code also makes the assumption that
unaligned access is okay (not true on all systems), but jemalloc only
hashes data structures that have sufficient alignment to dodge this
limitation.
diff --git a/test/unit/hash.c b/test/unit/hash.c
index 0446e52..abb394a 100644
--- a/test/unit/hash.c
+++ b/test/unit/hash.c
@@ -122,9 +122,15 @@
 	    (final[3] << 24);
 
 	switch (variant) {
+#ifdef JEMALLOC_BIG_ENDIAN
+	case hash_variant_x86_32: expected = 0x6213303eU; break;
+	case hash_variant_x86_128: expected = 0x266820caU; break;
+	case hash_variant_x64_128: expected = 0xcc622b6fU; break;
+#else
 	case hash_variant_x86_32: expected = 0xb0f57ee3U; break;
 	case hash_variant_x86_128: expected = 0xb3ece62aU; break;
 	case hash_variant_x64_128: expected = 0x6384ba69U; break;
+#endif
 	default: not_reached();
 	}