Fix compilation errors

Author: silver-popov

libunwind/src/Unwind-seh.cpp

@@ -163,7 +163,7 @@ _GCC_specific_handler(PEXCEPTION_RECORD ms_exc, PVOID frame, PCONTEXT ms_ctx,
     // If we were called by __libunwind_seh_personality(), indicate that
     // a handler was found; otherwise, initiate phase 2 by unwinding.
     if (ours && ms_exc->NumberParameters > 1)
-      return 4 /* ExceptionExecuteHandler in mingw */;
+      return (EXCEPTION_DISPOSITION)4 /* ExceptionExecuteHandler in mingw */;
     // This should never happen in phase 2.
     if (IS_UNWINDING(ms_exc->ExceptionFlags))
       _LIBUNWIND_ABORT("Personality indicated exception handler in phase 2!");
@@ -181,7 +181,7 @@ _GCC_specific_handler(PEXCEPTION_RECORD ms_exc, PVOID frame, PCONTEXT ms_ctx,
     // a handler was found; otherwise, it's time to initiate a collided
     // unwind to the target.
     if (ours && !IS_UNWINDING(ms_exc->ExceptionFlags) && ms_exc->NumberParameters > 1)
-      return 4 /* ExceptionExecuteHandler in mingw */;
+      return (EXCEPTION_DISPOSITION)4 /* ExceptionExecuteHandler in mingw */;
     // This should never happen in phase 1.
     if (!IS_UNWINDING(ms_exc->ExceptionFlags))
       _LIBUNWIND_ABORT("Personality installed context during phase 1!");