BUG: Fix rpath-link flag for SunPro C++ on Linux

This teaches Modules/Platform/Linux-SunPro-CXX.cmake the -rpath-link flag.  The
SunPro C++ compiler does not have a '-Wl,' option, so we just pass the flag
directly.

This problem was exposed by the ExportImport test now that it links an
executable through the C++ compiler with the -rpath-link flag.

Modules/Platform/Linux-SunPro-CXX.cmake

@@ -5,6 +5,7 @@ SET(CMAKE_SHARED_LIBRARY_CREATE_CXX_FLAGS "-G")
 SET(CMAKE_SHARED_LIBRARY_LINK_CXX_FLAGS "")
 SET(CMAKE_SHARED_LIBRARY_RUNTIME_CXX_FLAG "-R")
 SET(CMAKE_SHARED_LIBRARY_RUNTIME_CXX_FLAG_SEP ":")
+SET(CMAKE_SHARED_LIBRARY_RPATH_LINK_CXX_FLAG "-rpath-link ")
 SET(CMAKE_SHARED_LIBRARY_SONAME_CXX_FLAG "-h")
 SET(CMAKE_EXE_EXPORTS_CXX_FLAG "--export-dynamic")