[$] The first part of the 7.4 merge window

Since the merge window for 7.4 opened, there have been 6,753 non-merge changesets pulled into the mainline repository. Many more are expected, especially given the possibility that this merge window will be extended to three weeks. Still, even this initial set brought in a number of new features, in addition to the continued general cleanups and security fixes that the kernel has seen recently.