memory: stop overriding unused wcsdup()/_wcsdup() system functions

Also ban them via `checksrc`.

The code continues to use `_tcsdup()`.

Assisted-by: Daniel Stenberg

Closes curl#17840

Author: vszakats

lib/curl_memory.h

@@ -69,8 +69,6 @@
 
 #ifdef _WIN32
 #  ifdef UNICODE
-#    undef wcsdup
-#    undef _wcsdup
 #    undef _tcsdup
 #  else
 #    undef _tcsdup
@@ -155,10 +153,6 @@ extern curl_wcsdup_callback Curl_cwcsdup;
 
 #ifdef _WIN32
 #  ifdef UNICODE
-#    undef wcsdup
-#    define wcsdup(ptr) Curl_cwcsdup(ptr)
-#    undef _wcsdup
-#    define _wcsdup(ptr) Curl_cwcsdup(ptr)
 #    undef _tcsdup
 #    define _tcsdup(ptr) Curl_cwcsdup(ptr)
 #  else

lib/memdebug.h

@@ -142,10 +142,6 @@ CURL_EXTERN ALLOC_FUNC
 
 #ifdef _WIN32
 #  ifdef UNICODE
-#    undef wcsdup
-#    define wcsdup(ptr) curl_dbg_wcsdup(ptr, __LINE__, __FILE__)
-#    undef _wcsdup
-#    define _wcsdup(ptr) curl_dbg_wcsdup(ptr, __LINE__, __FILE__)
 #    undef _tcsdup
 #    define _tcsdup(ptr) curl_dbg_wcsdup(ptr, __LINE__, __FILE__)
 #  else

scripts/checksrc.pl

@@ -65,6 +65,8 @@
     "_tcsncat" => 1,
     "_wcscat" => 1,
     "_wcsncat" => 1,
+    "_wcsdup" => 1,
+    "wcsdup" => 1,
     "LoadLibrary" => 1,
     "LoadLibraryA" => 1,
     "LoadLibraryW" => 1,