Revert "Revert "Make the malloc(3) family of functions weak and make their non-weak""

This reverts commit e3e7b2e428c762085bf907715b00b997eda2c338.

Conflicts:
	contrib/jemalloc/include/jemalloc/jemalloc_FreeBSD.h
	include/malloc_np.h
	lib/libc/stdlib/jemalloc/Symbol.map