windows: Always set NOMINMAX to remove min/max macros

Reviewed-by: Francisco Jerez <currojerez@riseup.net>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/7680>

meson.build

@@ -988,6 +988,7 @@ elif host_machine.system() == 'windows'
       '-D_SCL_SECURE_NO_DEPRECATE',
       '-D_ALLOW_KEYWORD_MACROS',
       '-D_HAS_EXCEPTIONS=0', # Tell C++ STL to not use exceptions
+      '-DNOMINMAX',
     ]
   else
     pre_args += ['-D__MSVCRT_VERSION__=0x0700']

src/gallium/drivers/swr/rasterizer/common/os.h

@@ -39,7 +39,9 @@
 #undef NOMINMAX
 #define UNICODE
 #else
+#undef UNICODE
 #include <windows.h>
+#define UNICODE
 #endif
 #include <intrin.h>
 #include <cstdint>