stdlib: repair the Windows build

The recent change to enable the stack traces requires a dependency on
DbgHelp which we were not linking against.  Add the link.

Author: compnerd

stdlib/public/core/CMakeLists.txt

@@ -263,7 +263,7 @@ elseif(SWIFT_PRIMARY_VARIANT_SDK STREQUAL LINUX)
     list(APPEND swift_core_private_link_libraries swiftImageInspectionShared)
   endif()
 elseif(SWIFT_PRIMARY_VARIANT_SDK STREQUAL WINDOWS)
-  list(APPEND swift_core_private_link_libraries shell32)
+  list(APPEND swift_core_private_link_libraries shell32;DbgHelp)
 endif()
 
 option(SWIFT_CHECK_ESSENTIAL_STDLIB