MB-31350: Added s390x architecture support

Change-Id: If3b9c300aeeacbfb305ec98e953c70ff7f990b48
Reviewed-on: http://review.couchbase.org/100357
Reviewed-by: Dave Rigby <[email protected]>
Tested-by: Build Bot <[email protected]>

Author: kbhute-ibm

engines/ep/src/tagged_ptr.h

@@ -19,7 +19,7 @@
 
 #include <memory>
 
-#if !__x86_64__ && !_M_X64
+#if !__x86_64__ && !_M_X64 && !__s390x__
 #error "TaggedPtr is x64 specific code.  Not tested on other architectures"
 #endif