Don't define wxSIZE_T_IS_UINT for Cygwin unconditionally.

This breaks 64 bit Cygwin builds and is unnecessary for 32 bit ones where
configure already defines wxSIZE_T_IS_UINT correctly.

Closes #16130.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_3_0_BRANCH@76509 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Use __WIN64__ instead of MSVC-specific _WIN64 in wxIsPlatform64Bit().

Make the code work correctly for 64 bit builds with other compilers, e.g. gcc.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_3_0_BRANCH@76510 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Define __WIN64__ for 64 bit wxMSW builds with gcc too.

Previously __WIN64__ was only defined for 64 bit builds with MSVC, which
resulted in many problems when using 64 bit Cygwin compiler.

Also don't use MSVC-specific __int64 but our wxInt64 for WX{L,W}PARAM and
WXLRESULT definitions in 64 bit builds.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_3_0_BRANCH@76511 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Don't use DWORD and WXDWORD interchangeably in wxMSW code.

WXDWORD is defined as unsigned long, while DWORD is defined as unsigned int in
64 bit builds using Cygwin gcc, so they are not the same type (although they
do have the same size) and using the latter instead of the former in the
function definition results in errors in this build configuration.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_3_0_BRANCH@76512 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Add casts from long to LONG to fix 64 bit Cygwin wxMSW build.

In 64 bits, LONG is actually defined as int in Cygwin gcc headers, so is
different from long -- even if both types use identical representation.

Just add the casts to fix this for now, as this is the smallest ABI-preserving
change. Ideally, something better and less ugly would need to be done in the
future.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_3_0_BRANCH@76513 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Don't use LCID and WXLCID interchangeably in wxMSW code.

Similarly to the problem with WXDWORD and DWORD, LCID is actually an unsigned
int and not unsigned long in 64 bit Cygwin builds, so it's a different type.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_3_0_BRANCH@76514 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Don't use _{get,ch}drive() functions in Cygwin builds.

They are not available there when not using MinGW headers, e.g. in 64 bit
builds.

Also simplify the code by using wxHAS_DRIVE_FUNCTIONS instead of complicated
(and sometimes negated) checks for MinGW32 version.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_3_0_BRANCH@76515 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Fix tests for __WXMSW__ in non-GUI-only code.

__WXMSW__ is not defined when compiling wxBase, so the tests which were meant
to prevent using Unix event loop classes under Cygwin (under which both
__UNIX__ and __WINDOWS__, but not __WXMSW__, are defined) failed, breaking
compilation of all wxEventLoop-related code in wxBase in Cygwin builds.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_3_0_BRANCH@76516 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Use DWORD instead of unsigned long in wxFileSystemWatcher wxMSW code.

These two types are not the same in 64 bit Cygwin builds, so fix the build by
just using DWORD everywhere.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_3_0_BRANCH@76517 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Fix cast from "void*" to integer type in wxThread::Exit() for non-MSVC.

This fixes another problem in 64 bit Cygwin build.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_3_0_BRANCH@76518 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Fix print preview in 64 bit MinGW wxMSW builds.

Don't hardcode wrong PRINTDLG structure size for 64 bit builds.

In fact, don't hardcode it at all as it just doesn't seem to be necessary to
do it, the comment about Cygwin getting it wrong seems to be out of date.

Closes #16256.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_3_0_BRANCH@76519 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775