Either the VS2003 compilers used for 32 bit or the April 2005 SDK 64 bit compiler
used for 64 bit JDK apparently had a bug requiring this pragma :

  37 // Enabling optimizations in this file causes incorrect code to be
  38 // generated; can not figure out how to turn down optimization for one
  39 // file in the IDE on Windows
  40 #ifdef WIN32
  41 # pragma optimize ( "", off )
  42 #endif

That caused some conflicts with VS2010 (see the source code for the details)
and required additionally that "__declspec(safebuffers)" be added to the
declarations of two functions.

However its quite possible that the VS2010 compilers no longer have the
original optimisation bug, and all these workarounds can be removed, and
presumably we'd get some performance benefit too.

So as soon as VS2010 is being used for JDK 7 builds, someone with
appropriate expertise should test if the optimisation problems are gone
and make the appropriate changes.