[STLPORT] Fix MSVC x64 build.

Timo, can you check whether this disabled code block is really needed?

sdk/include/c++/stlport/stl/config/_reactos.h

@@ -302,6 +302,8 @@
 // Calling convention
 #define _STLP_CALL __cdecl
 
+#if 0
+
 #ifdef _M_AMD64
 #ifdef __cplusplus
 extern "C" {
@@ -323,6 +325,8 @@ extern "C" {
 #define __cdecl__
 #endif /* _M_AMD64 */
 
+#endif
+
 // Include stlport windows specifics
 #include "_windows.h"