squelch C4232 warnings on MSVC builds

C4232 appertains to the identity of dllimported functions [1]. The
address of dllimport'ed functions are not guaranteed to maintain
identity as the address will be the address of the IAT thunk, which is
module specific.  Two modules which bind to the same implementation may
have different addresses. However, since the use of this is for `free`,
it should be relatively safe as we do not expect to perform pointer
identity comparisons.

[1] https://learn.microsoft.com/en-us/cpp/error-messages/compiler-warnings/compiler-warning-level-4-c4232?view=msvc-170

CMakeLists.txt

@@ -46,7 +46,7 @@ add_compile_options($<$<CONFIG:Debug>:-DCMARK_DEBUG_NODES>)
 # so that CMark may be used in projects with non-C languages.
 function(cmark_add_compile_options target)
   if(MSVC)
-    target_compile_options(${target} PRIVATE /W4 /wd4706 /we4244 /we4267)
+    target_compile_options(${target} PRIVATE /W4 /wd4706 /wd4232 /we4244 /we4267)
     if(MSVC_VERSION LESS 1800)
       target_compile_options(${target} PRIVATE /TP)
     endif()