py/runtime: Move mp_exc_recursion_depth to runtime and rename to raise.

For consistency this helper function is renamed to match the other
exception helpers, and moved to their location in runtime.c.
diff --git a/py/runtime.c b/py/runtime.c
index 457266c..5fd053e 100644
--- a/py/runtime.c
+++ b/py/runtime.c
@@ -1456,3 +1456,10 @@
 NORETURN void mp_raise_NotImplementedError(const char *msg) {
     mp_raise_msg(&mp_type_NotImplementedError, msg);
 }
+
+#if MICROPY_STACK_CHECK
+NORETURN void mp_raise_recursion_depth(void) {
+    nlr_raise(mp_obj_new_exception_arg1(&mp_type_RuntimeError,
+        MP_OBJ_NEW_QSTR(MP_QSTR_maximum_space_recursion_space_depth_space_exceeded)));
+}
+#endif
diff --git a/py/runtime.h b/py/runtime.h
index 3f0d110..a19f64c 100644
--- a/py/runtime.h
+++ b/py/runtime.h
@@ -151,7 +151,7 @@
 NORETURN void mp_raise_TypeError(const char *msg);
 NORETURN void mp_raise_NotImplementedError(const char *msg);
 NORETURN void mp_raise_OSError(int errno_);
-NORETURN void mp_exc_recursion_depth(void);
+NORETURN void mp_raise_recursion_depth(void);
 
 #if MICROPY_BUILTIN_METHOD_CHECK_SELF_ARG
 #undef mp_check_self
diff --git a/py/stackctrl.c b/py/stackctrl.c
index 11165b9..5c07796 100644
--- a/py/stackctrl.c
+++ b/py/stackctrl.c
@@ -48,14 +48,9 @@
     MP_STATE_THREAD(stack_limit) = limit;
 }
 
-NORETURN void mp_exc_recursion_depth(void) {
-    nlr_raise(mp_obj_new_exception_arg1(&mp_type_RuntimeError,
-        MP_OBJ_NEW_QSTR(MP_QSTR_maximum_space_recursion_space_depth_space_exceeded)));
-}
-
 void mp_stack_check(void) {
     if (mp_stack_usage() >= MP_STATE_THREAD(stack_limit)) {
-        mp_exc_recursion_depth();
+        mp_raise_recursion_depth();
     }
 }
 
diff --git a/py/vm.c b/py/vm.c
index e667972..5011af5 100644
--- a/py/vm.c
+++ b/py/vm.c
@@ -935,7 +935,7 @@
                         #if MICROPY_STACKLESS_STRICT
                         else {
                         deep_recursion_error:
-                            mp_exc_recursion_depth();
+                            mp_raise_recursion_depth();
                         }
                         #else
                         // If we couldn't allocate codestate on heap, in