generate compile_commands.json, e.g. to be used by VS Code intellisense

To tell to vsclode the path to include files add to O2/.vscode/settings.json
{
  "C_Cpp.default.compileCommands": "${ALIBUILD_WORK_DIR}/BUILD/O2-latest/O2/compile_commands.json"
}

Author: shahor02

CMakeLists.txt

@@ -24,6 +24,7 @@ include(CTest)
 # Would better fit inside GPU/CMakeLists.txt, but include GPU/Common directly
 set(ALIGPU_BUILD_TYPE "O2")
 
+set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
 set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} ${CMAKE_CURRENT_SOURCE_DIR}/cmake)
 string(TOUPPER "${CMAKE_BUILD_TYPE}" CMAKE_BUILD_TYPE_UPPER)
 set_property(GLOBAL PROPERTY REPORT_UNDEFINED_PROPERTIES)