AP_Scripting: Fix up some warnings

-Remove some non forward declared issues
  -Remove forced min/max values from the enum range check

libraries/AP_Scripting/generator/src/main.c

@@ -845,7 +845,6 @@ void emit_checker(const struct type t, int arg_number, const char *indentation,
         forced_min = "INT16_MIN";
         forced_max = "INT16_MAX";
         break;
-      case TYPE_ENUM: // enums are assumed to only ever be within the int32_t space
       case TYPE_INT32_T:
         forced_min = "INT32_MIN";
         forced_max = "INT32_MAX";
@@ -862,6 +861,9 @@ void emit_checker(const struct type t, int arg_number, const char *indentation,
         forced_min = "0";
         forced_max = "UINT16_MAX";
         break;
+      case TYPE_ENUM:
+        forced_min = forced_max = NULL;
+        break;
       case TYPE_NONE:
         return; // nothing to do here, this should potentially be checked outside of this, but it makes an easier implementation to accept it
       case TYPE_STRING:
@@ -899,11 +901,19 @@ void emit_checker(const struct type t, int arg_number, const char *indentation,
 
     // range check
     if (t.range != NULL) {
-      fprintf(source, "%sluaL_argcheck(L, ((raw_data_%d >= MAX(%s, %s)) && (raw_data_%d <= MIN(%s, %s))), %d, \"%s out of range\");\n",
-              indentation,
-              arg_number, t.range->low, forced_min,
-              arg_number, t.range->high, forced_max,
-              arg_number, name);
+      if ((forced_min != NULL) && (forced_max != NULL)) {
+        fprintf(source, "%sluaL_argcheck(L, ((raw_data_%d >= MAX(%s, %s)) && (raw_data_%d <= MIN(%s, %s))), %d, \"%s out of range\");\n",
+                indentation,
+                arg_number, t.range->low, forced_min,
+                arg_number, t.range->high, forced_max,
+                arg_number, name);
+       } else {
+        fprintf(source, "%sluaL_argcheck(L, ((raw_data_%d >= %s) && (raw_data_%d <= %s)), %d, \"%s out of range\");\n",
+                indentation,
+                arg_number, t.range->low,
+                arg_number, t.range->high,
+                arg_number, name);
+       }
     }
 
     // down cast

libraries/AP_Scripting/lua_bindings.cpp

@@ -26,8 +26,7 @@ int check_arguments(lua_State *L, int expected_arguments, const char *fn_name) {
 
 // servo binding
 
-int lua_servo_set_output_pwm(lua_State *L);
-int lua_servo_set_output_pwm(lua_State *L) {
+static int lua_servo_set_output_pwm(lua_State *L) {
     check_arguments(L, 2, "set_output_pwm");
 
     const SRV_Channel::Aux_servo_function_t servo_function = (SRV_Channel::Aux_servo_function_t)luaL_checkinteger(L, -2);
@@ -44,7 +43,7 @@ int lua_servo_set_output_pwm(lua_State *L) {
 }
 
 // millis
-int lua_millis(lua_State *L) {
+static int lua_millis(lua_State *L) {
     check_arguments(L, 0, "millis");
 
     new_uint32_t(L);

libraries/AP_Scripting/lua_boxed_numerics.cpp

@@ -1,6 +1,7 @@
 #include <AP_HAL/AP_HAL.h>
 #include "lua_boxed_numerics.h"
 
+
 extern const AP_HAL::HAL& hal;
 
 int new_uint32_t(lua_State *L) {
@@ -16,7 +17,7 @@ uint32_t * check_uint32_t(lua_State *L, int arg) {
     return static_cast<uint32_t *>(data);
 }
 
-uint32_t coerce_to_uint32_t(lua_State *L, int arg) {
+static uint32_t coerce_to_uint32_t(lua_State *L, int arg) {
     { // userdata
         const uint32_t * ud = static_cast<uint32_t *>(luaL_testudata(L, arg, "uint32_t"));
         if (ud != nullptr) {

libraries/AP_Scripting/lua_generated_bindings.cpp

@@ -478,7 +478,7 @@ static int GCS_send_text(lua_State *L) {
     }
 
     const lua_Integer raw_data_2 = luaL_checkinteger(L, 2);
-    luaL_argcheck(L, ((raw_data_2 >= MAX(MAV_SEVERITY_EMERGENCY, INT32_MIN)) && (raw_data_2 <= MIN(MAV_SEVERITY_DEBUG, INT32_MAX))), 2, "argument out of range");
+    luaL_argcheck(L, ((raw_data_2 >= MAV_SEVERITY_EMERGENCY) && (raw_data_2 <= MAV_SEVERITY_DEBUG)), 2, "argument out of range");
     const MAV_SEVERITY data_2 = static_cast<MAV_SEVERITY>(raw_data_2);
     const char * data_3 = luaL_checkstring(L, 3);
     ud->send_text(