Get VC++ building again

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@19140 91177308-0d34-0410-b5e6-96231b3b80d8

lib/System/DynamicLibrary.cpp

@@ -12,6 +12,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/System/DynamicLibrary.h"
+#include "llvm/Config/config.h"
 
 // It is not possible to use ltdl.c on VC++ builds as the terms of its LGPL
 // license and special exception would cause all of LLVM to be placed under
@@ -19,7 +20,7 @@
 // used, and obviously libtool is not used with Visual Studio.  An entirely
 // separate implementation is provided in win32/DynamicLibrary.cpp.
 
-#ifdef _WIN32
+#ifdef LLVM_ON_WIN32
 
 #include "win32/DynamicLibrary.cpp"
 
@@ -148,4 +149,4 @@ void *DynamicLibrary::GetAddressOfSymbol(const char *symbolName) {
   return lt_dlsym((lt_dlhandle) handle, symbolName);
 }
 
-#endif // _WIN32
+#endif // LLVM_ON_WIN32