Workarounds for missing -municode support

Author: Blackhex

winsup/testsuite/mingw/Makefile.am

@@ -27,5 +27,7 @@ cygload_LDFLAGS=-static -Wl,-e,cygloadCRTStartup
 
 winchild_SOURCES = \
 	../winsup.api/posix_spawn/winchild.c
+if TARGET_X86_64
 winchild_LDFLAGS=-municode
+endif
 winchild_LDADD=-lntdll

winsup/testsuite/winsup.api/posix_spawn/winchild.c

@@ -3,7 +3,18 @@
 #include <winternl.h>
 #include <ctype.h>
 #include <stdio.h>
+#include <stdlib.h>
 
+#if defined(__aarch64__)
+int WinMain(
+  HINSTANCE hInstance,
+  HINSTANCE hPrevInstance,
+  LPSTR lpCmdLine,
+  int nShowCmd
+) {
+
+}
+#endif
 
 int wmain (int argc, wchar_t **argv)
 {