Add support for generating clang compilation database by default (#35629)

compilation db by default

SConstruct

@@ -39,10 +39,6 @@ AddOption('--clazy',
           action='store_true',
           help='build with clazy')
 
-AddOption('--compile_db',
-          action='store_true',
-          help='build clang compilation database')
-
 AddOption('--ccflags',
           action='store',
           type='string',
@@ -214,8 +210,7 @@ if arch == "Darwin":
   darwin_rpath_link_flags = [f"-Wl,-rpath,{path}" for path in env["RPATH"]]
   env["LINKFLAGS"] += darwin_rpath_link_flags
 
-if GetOption('compile_db'):
+env.CompilationDatabase('compile_commands.json')
-  env.CompilationDatabase('compile_commands.json')
 
 # Setup cache dir
 cache_dir = '/data/scons_cache' if AGNOS else '/tmp/scons_cache'