RFR: Fix Windows builds

[Aleksey Shipilev]

Windows builds are currently failing with:


c:\buildbot\worker\build-shenandoah-jdkx-windows\build\src\hotspot\share\gc\shenandoah\shenandoahOldGC.cpp(149): error C2131: expression did not evaluate to a constant
c:\buildbot\worker\build-shenandoah-jdkx-windows\build\src\hotspot\share\gc\shenandoah\shenandoahOldGC.cpp(149): note: failure was caused by a read of a variable outside its lifetime
c:\buildbot\worker\build-shenandoah-jdkx-windows\build\src\hotspot\share\gc\shenandoah\shenandoahOldGC.cpp(149): note: see usage of 'coalesce_and_fill_regions_count'
make[3]: *** [lib/CompileJvm.gmk:143: /cygdrive/c/buildbot/worker/build-shenandoah-jdkx-windows/build/build/windows-x86_64-server-fastdebug/hotspot/variant-server/libjvm/objs/shenandoahOldGC.obj] Error 1


...and:


c:\buildbot\worker\build-shenandoah-jdkx-windows\build\src\hotspot\share\gc\shenandoah\heuristics\shenandoahOldHeuristics.cpp(239): error C2220: the following warning is treated as an error
c:\buildbot\worker\build-shenandoah-jdkx-windows\build\src\hotspot\share\gc\shenandoah\heuristics\shenandoahOldHeuristics.cpp(239): warning C4267: '=': conversion from 'size_t' to 'uint', possible loss of data
c:\buildbot\worker\build-shenandoah-jdkx-windows\build\src\hotspot\share\gc\shenandoah\heuristics\shenandoahOldHeuristics.cpp(240): warning C4267: '=': conversion from 'size_t' to 'uint', possible loss of data
c:\buildbot\worker\build-shenandoah-jdkx-windows\build\src\hotspot\share\gc\shenandoah\heuristics\shenandoahOldHeuristics.cpp(241): warning C4267: '=': conversion from 'size_t' to 'uint', possible loss of data
c:\buildbot\worker\build-shenandoah-jdkx-windows\build\src\hotspot\share\gc\shenandoah\heuristics\shenandoahOldHeuristics.cpp(255): warning C4267: '=': conversion from 'size_t' to 'uint', possible loss of data
make[3]: *** [lib/CompileJvm.gmk:143: /cygdrive/c/buildbot/worker/build-shenandoah-jdkx-windows/build/build/windows-x86_64-server-fastdebug/hotspot/variant-server/libjvm/objs/shenandoahOldHeuristics.obj] Error 1
make[2]: *** [make/Main.gmk:252: hotspot-server-libs] Error 2


Additional testing:
 - [x] Windows x86_64 builds
 - [x] Linux x86_64 hotspot_gc_shenandoah

-------------

Commit messages:
 - Fix Windows builds

Changes: https://git.openjdk.java.net/shenandoah/pull/35/files
 Webrev: https://webrevs.openjdk.java.net/?repo=shenandoah&pr=35&range=00
  Stats: 13 lines in 3 files changed: 4 ins; 1 del; 8 mod
  Patch: https://git.openjdk.java.net/shenandoah/pull/35.diff
  Fetch: git fetch https://git.openjdk.java.net/shenandoah pull/35/head:pull/35

PR: https://git.openjdk.java.net/shenandoah/pull/35