Implement RtlInitAnsiStringEx.

diff --git a/include/winternl.h b/include/winternl.h
index e8e6998..060f8a7 100644
--- a/include/winternl.h
+++ b/include/winternl.h
@@ -2070,6 +2070,7 @@
 NTSTATUS  WINAPI RtlImpersonateSelf(SECURITY_IMPERSONATION_LEVEL);
 void      WINAPI RtlInitString(PSTRING,PCSZ);
 void      WINAPI RtlInitAnsiString(PANSI_STRING,PCSZ);
+NTSTATUS  WINAPI RtlInitAnsiStringEx(PANSI_STRING,PCSZ);
 void      WINAPI RtlInitUnicodeString(PUNICODE_STRING,PCWSTR);
 NTSTATUS  WINAPI RtlInitUnicodeStringEx(PUNICODE_STRING,PCWSTR);
 NTSTATUS  WINAPI RtlInitializeCriticalSection(RTL_CRITICAL_SECTION *);