MSVC changes

Add support for compilation on x64 toolchain (x86 cl.exe was running out of heap space in vm.cpp)

Also took the opportunity to change compile optimisation from /Ox to /O2, as /O2 provides better optimisation than does /Ox

Also, we shouldn't be explicitely setting compiler tool defines (__cpp_lib_bitops), so remove that from types.h

3rdparty/7zlib.vcxproj

@@ -111,6 +111,9 @@
   </PropertyGroup>
   <Import Project="..\common_default.props" />
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.Default.props" />
+  <PropertyGroup>
+    <PreferredToolArchitecture>x64</PreferredToolArchitecture>
+  </PropertyGroup>
   <Import Project="..\common_default_macros.props" />
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'" Label="Configuration">
     <ConfigurationType>StaticLibrary</ConfigurationType>