Jemalloc updated to 4.4.0.

The original jemalloc source tree was modified to:

1. Remove the configure error that prevents nested builds.
2. Insert the Redis private Jemalloc API in order to allow the
Redis fragmentation function to work.

deps/jemalloc/test/unit/math.c

@@ -5,6 +5,10 @@
 
 #include <float.h>
 
+#ifdef __PGI
+#undef INFINITY
+#endif
+
 #ifndef INFINITY
 #define	INFINITY (DBL_MAX + DBL_MAX)
 #endif