py/objstr: Use MICROPY_FULL_CHECKS for range checking when constructing bytes.

Split this setting from MICROPY_CPYTHON_COMPAT. The idea is to be able to
keep MICROPY_CPYTHON_COMPAT disabled, but still pass more of regression
testsuite. In particular, this fixes last failing test in basics/ for
Zephyr port.

py/mpconfig.h

@@ -556,6 +556,15 @@ typedef double mp_float_t;
 #define MICROPY_CPYTHON_COMPAT (1)
 #endif
 
+// Perform full checks as done by CPython. Disabling this
+// may produce incorrect results, if incorrect data is fed,
+// but should not lead to MicroPython crashes or similar
+// grave issues (in other words, only user app should be,
+// affected, not system).
+#ifndef MICROPY_FULL_CHECKS
+#define MICROPY_FULL_CHECKS (1)
+#endif
+
 // Whether POSIX-semantics non-blocking streams are supported
 #ifndef MICROPY_STREAMS_NON_BLOCK
 #define MICROPY_STREAMS_NON_BLOCK (0)

py/objstr.c

@@ -236,7 +236,7 @@ STATIC mp_obj_t bytes_make_new(const mp_obj_type_t *type_in, size_t n_args, size
     mp_obj_t item;
     while ((item = mp_iternext(iterable)) != MP_OBJ_STOP_ITERATION) {
         mp_int_t val = mp_obj_get_int(item);
-        #if MICROPY_CPYTHON_COMPAT
+        #if MICROPY_FULL_CHECKS
         if (val < 0 || val > 255) {
             mp_raise_ValueError("bytes value out of range");
         }