Add NOMINMAX define to CMakeLists.txt for Windows

This was causing a build error for open source (in user_secure_windows_internal).

PiperOrigin-RevId: 246834626

Author: ryanmeier

auth/CMakeLists.txt

@@ -205,6 +205,12 @@ else()
   add_definitions(-include assert.h -include string.h)
 endif()
 
+# Ensure min/max macros don't get declared on Windows
+# (so we can use std::min/max)
+if(MSVC)
+  add_definitions(-DNOMINMAX)
+endif()
+
 if(IOS)
   # Enable Automatic Reference Counting (ARC).
   set_property(