py: Make it easy to build without MICROPY_PY_BUILTINS_COMPLEX.

Automagically skip related modules.

py/modcmath.c

@@ -26,7 +26,7 @@
 
 #include "py/builtin.h"
 
-#if MICROPY_PY_BUILTINS_FLOAT && MICROPY_PY_CMATH
+#if MICROPY_PY_BUILTINS_FLOAT && MICROPY_PY_BUILTINS_COMPLEX && MICROPY_PY_CMATH
 
 #include <math.h>
 

py/objmodule.c

@@ -150,7 +150,7 @@ STATIC const mp_rom_map_elem_t mp_builtin_module_table[] = {
 #if MICROPY_PY_MATH
     { MP_ROM_QSTR(MP_QSTR_math), MP_ROM_PTR(&mp_module_math) },
 #endif
-#if MICROPY_PY_CMATH
+#if MICROPY_PY_BUILTINS_COMPLEX && MICROPY_PY_CMATH
     { MP_ROM_QSTR(MP_QSTR_cmath), MP_ROM_PTR(&mp_module_cmath) },
 #endif
 #endif