HPCC-14790 Overwrite Cmake supplied RelDebWithInfo w Release cxx flags

Signed-off-by: Michael Gardner <michael.gardner@lexisnexis.com>

cmake_modules/commonSetup.cmake

@@ -244,6 +244,7 @@ IF ("${COMMONSETUP_DONE}" STREQUAL "")
           SET (CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wparentheses")
         endif ()
       endif ()
+      SET (CMAKE_CXX_FLAGS_RELWITHDEBINFO "${CMAKE_CXX_FLAGS_RELEASE}")
       if (GENERATE_COVERAGE_INFO)
         message ("Build system with coverage.")
         SET (CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fprofile-arcs -ftest-coverage")