64-bit Windows on AMD64/Intel EM64T is somewhat supported in the 7.0
and later release.  A collector can be built with Microsoft Visual C++ 2005
or with mingw-w64 gcc.

NT_MAKEFILE has been used in this environment.  Type
"nmake -f NT_MAKEFILE cpu=AMD64 nodebug=1" in a Visual C++ command line
window to build the release variant of the dynamic library with threads
support and the usual test programs.
To verify that the collector is at least somewhat functional, run gctest.exe.
This should create gctest.gc.log after a few seconds.

Test_cpp.exe might not run correctly in case of dynamic GC linking.  (It seems
that we're getting wrong instances of operator new/delete in some cases.)

This process is completely analogous to NT_MAKEFILE usage
for the 32-bit library version.

A similar procedure using NT_MAKEFILE is applicable to build the static
library - just pass "make_as_lib=1" as an extra argument to nmake.
If needed, it is also possible to build the library without threads
support - this could be done by passing "nothreads=1" argument to nmake.

Note that some warnings have been explicitly turned off in the makefile.

VC++ note: to suppress warnings -D_CRT_SECURE_NO_DEPRECATE is used.

gcc note: -fno-strict-aliasing should be used if optimizing.