[cmake] Change deprecated $<CONFIG> to $<CONFIGURATION>. NFC
See rL357338 for a similar change. The informational expression
$<CONFIGURATION> has been deprecated since CMake 3.0
@@ -615,7 +615,7 @@ macro(add_custom_libcxx name prefix)
set(run_clean "$(MAKE)" "-C" "${BINARY_DIR}" "clean")
else()
set(run_clean ${CMAKE_COMMAND} --build ${BINARY_DIR} --target clean
- --config "$<CONFIGURATION>")
+ --config "$<CONFIG>")
endif()
ExternalProject_Add_Step(${name} clean
