locking-core-2021-02-17

 - Core locking primitives updates:

    - Remove mutex_trylock_recursive() from the API - no users left
    - Simplify + constify the futex code a bit

 - Lockdep updates:

    - Teach lockdep about local_lock_t
    - Add CONFIG_DEBUG_IRQFLAGS=y debug config option to check for
      potentially unsafe IRQ mask restoration patterns. (I.e.
      calling raw_local_irq_restore() with IRQs enabled.)
    - Add wait context self-tests
    - Fix graph lock corner case corrupting internal data structures
    - Fix noinstr annotations

 - LKMM updates:

    - Simplify the litmus tests
    - Documentation fixes

 - KCSAN updates:

    - Re-enable KCSAN instrumentation in lib/random32.c

 - Misc fixes:

    - Don't branch-trace static label APIs
    - DocBook fix
    - Remove stale leftover empty file

Signed-off-by: Ingo Molnar <mingo@kernel.org>