Drop support for lcc as a C compiler. lcc itself does not seem to have been updated since around 2010 and Mercury's support for it has not been updated for quite a while before that. Derivatives of lcc, for example lcc-win32, would almost certainly need to be treated separately anyway, so this change doesn't affect them (i.e. they are already not supported). configure.ac: m4/mercury.m4: Do not recognise lcc as a C compiler. Unrelated change: remove residual support for a.out executables on Linux. scripts/mgnuc_file_opts.sh-subr: Do not define the macros __EXTENSIONS__ and _GNU_SOURCE if the mgnuc script is invoked with --no-ansi. This was originally done to support lcc on Linux. Doing so on *all* systems as this code actually does is not a good idea. (If it becomes necessary to reinstate this behaviour on some system, it should be controlled from the configure script not here.) runtime/mercury_wrapper.c: Delete a workaround for lcc. scripts/mgnuc.in: scripts/ml.in: compiler/compile_target_code.m: compiler/handle_options.m: compiler/globals.m: compiler/ml_code_gen.m: Delete support for lcc. README.lcc: Delete this file.