Platform: improve WinSDK coverage further

Additional APISets are required to implement the Foundation API surface.
Expand the module to include that.  Unfortunately, I have not been able
to get the ImageHelp or the DebugHelp APIs or the RTLSupport APISet
covered under the module.  Those are required to get stack captures to
work.

Author: compnerd

stdlib/public/Platform/winsdk.modulemap

@@ -53,6 +53,19 @@ module WinSDK [system] [extern_c] {
       header "synchapi.h"
       export *
     }
+
+    // api-ms-win-core-sysinfo-l1-1-0.dll
+    module sysinfo {
+      header "sysinfoapi.h"
+      export *
+    }
+
+    // api-ms-win-core-timezone-l1-1-0.dll
+    module timezone {
+      header "timezoneapi.h"
+      export *
+    }
   }
+
 }