Generate a C++ function for EnumValues{{ENUM_NAME}} (#4337)

* enables "for each" logic on enumeration types

tests/monster_test_generated.h

@@ -39,6 +39,15 @@ enum Color {
   Color_ANY = 11
 };
 
+inline Color (&EnumValuesColor())[3] {
+  static Color values[] = {
+    Color_Red,
+    Color_Green,
+    Color_Blue
+  };
+  return values;
+}
+
 inline const char **EnumNamesColor() {
   static const char *names[] = {
     "Red",
@@ -68,6 +77,16 @@ enum Any {
   Any_MAX = Any_MyGame_Example2_Monster
 };
 
+inline Any (&EnumValuesAny())[4] {
+  static Any values[] = {
+    Any_NONE,
+    Any_Monster,
+    Any_TestSimpleTableWithEnum,
+    Any_MyGame_Example2_Monster
+  };
+  return values;
+}
+
 inline const char **EnumNamesAny() {
   static const char *names[] = {
     "NONE",

tests/namespace_test/namespace_test1_generated.h

@@ -21,6 +21,15 @@ enum EnumInNestedNS {
   EnumInNestedNS_MAX = EnumInNestedNS_C
 };
 
+inline EnumInNestedNS (&EnumValuesEnumInNestedNS())[3] {
+  static EnumInNestedNS values[] = {
+    EnumInNestedNS_A,
+    EnumInNestedNS_B,
+    EnumInNestedNS_C
+  };
+  return values;
+}
+
 inline const char **EnumNamesEnumInNestedNS() {
   static const char *names[] = {
     "A",

tests/union_vector/union_vector_generated.h

@@ -28,6 +28,19 @@ enum Character {
   Character_MAX = Character_Unused
 };
 
+inline Character (&EnumValuesCharacter())[7] {
+  static Character values[] = {
+    Character_NONE,
+    Character_MuLan,
+    Character_Rapunzel,
+    Character_Belle,
+    Character_BookFan,
+    Character_Other,
+    Character_Unused
+  };
+  return values;
+}
+
 inline const char **EnumNamesCharacter() {
   static const char *names[] = {
     "NONE",