Added extern "C" if __cplusplus is defined.

include/tapi.h

diff --git a/include/tapi.h b/include/tapi.h
index a7fe1db..4a80afa 100644
--- a/include/tapi.h
+++ b/include/tapi.h
@@ -9,6 +9,10 @@
 
 #include "windef.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif /* defined(__cplusplus) */
+
 typedef HANDLE HCALL, *LPHCALL;
 typedef HANDLE HLINE, *LPHLINE;
 typedef HANDLE HLINEAPP, *LPHLINEAPP;
@@ -624,4 +628,8 @@
 DWORD WINAPI tapiGetLocationInfo(LPSTR,LPSTR);
 DWORD WINAPI tapiRequestMakeCall(LPCSTR,LPCSTR,LPCSTR,LPCSTR);
 
+#ifdef __cplusplus
+} /* extern "C" */
+#endif /* defined(__cplusplus) */
+
 #endif /* __WINE_TAPI_H */