RFR: 8200550: Xcode 9.3 produce warning on heapRegionSet.hpp

[Kim Barrett]

Please review this fix of a couple of macro definitions that have
"defined" expressions in the expansion.  Such code has undefined
behavior: C++03 16.1/3.  Xcode 9.3 warns about such code.

The fix for HEAP_REGION_SET_FORCE_VERIFY is a straight-forward change
to use #ifdef ASSERT to define it appropriately.

The fix for TAIL_CALL is more interesting.  The code previously
involved "defined(WINDOWS)".  It turns out we don't define WINDOWS!
The correct macro to test is _WINDOWS.

Because WINDOWS is not defined when building for Windows, one might
think the conditional would go the wrong way.  But with the old
definition of TAIL_CALL, Visual Studio was deciding that "#if
!TAIL_CALL" should be selected anyway; it seems to be interpreting the
expression in some unexpected way that accidentally produced the
result we wanted.  (Since it's undefined behavior, it can do
anything.)

I also fixed vmError.cpp's incorrect "#ifdef WINDOWS" to use _WINDOWS.

CR:
https://bugs.openjdk.java.net/browse/JDK-8200550

Webrev:
http://cr.openjdk.java.net/~kbarrett/8200550/open.00/

Testing:
{jdk,hs}-tier{1,2,3} on all Oracle supported platforms.

Note that hs-tier2 contains NMT/CheckForProperDetailStackTrace, which
specifically tests the nativeCallStack code being modified here.