spinlock configure control

With the applied patch, --without-spinlocks will not use spinlock code
in the build. In CVS HEAD, this option has no affect if you have
spinlocks on your platform.

-- 
  Bruce Momjian                        |  http://candle.pha.pa.us
  pgman@candle.pha.pa.us               |  (610) 359-1001
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