Merge pull request #13447 from richardkchapman/aws-osx

HPCC-23632 Move the AWS support libraries

Reviewed-by: Gavin Halliday <ghalliday@hpccsystems.com>

system/aws/CMakeLists.txt

@@ -4,7 +4,7 @@ if(USE_AWS)
 
     project(aws)
     set(AWS_SDK_CPP_SOURCE_DIR ${CMAKE_CURRENT_SOURCE_DIR}/aws-sdk-cpp)
-    if (NOT CMAKE_CXX_COMPILER_VERSION VERSION_LESS 7.0.0)
+    if (CMAKE_COMPILER_IS_GNUCXX AND NOT CMAKE_CXX_COMPILER_VERSION VERSION_LESS 7.0.0)
       set(EXTERNAL_SQS_CXX_FLAGS "-Wno-error=implicit-fallthrough -Wno-error=int-in-bool-context -Wno-error=format-nonliteral" )
     endif()