K 10
svn:author
V 6
emaste
K 8
svn:date
V 27
2020-01-23T14:11:02.586818Z
K 7
svn:log
V 623
Apply r355819 to sparc64 - fix assertion failure after r355784

From r355819:
Repeat the spinlock_enter/exit pattern from amd64 on other architectures
to fix an assert violation introduced in r355784.  Without this
spinlock_exit() may see owepreempt and switch before reducing the
spinlock count.  amd64 had been optimized to do a single critical
enter/exit regardless of the number of spinlocks which avoided the
problem and this optimization had not been applied elsewhere.

This is completely untested - I have no obsolete Sparc hardware - but
someone did try testing recent changes on sparc64 (PR 243534).

PR:		243534

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