Use dedicated error for enum case conflict

Author: prateekbhujel

Zend/tests/enum/gh21760.phpt

@@ -16,4 +16,4 @@ enum Direction {
 
 ?>
 --EXPECTF--
-Fatal error: Direction and X define the same constant (Up) in the composition of Direction. However, the definition differs and is considered incompatible. Class was composed in %s on line %d
+Fatal error: Cannot use trait X, because constant Up conflicts with enum case Direction::Up in %s on line %d

Zend/zend_inheritance.c

@@ -2757,6 +2757,18 @@ static void emit_incompatible_trait_constant_error(
 	);
 }
 
+static void emit_trait_constant_enum_case_conflict_error(
+	const zend_class_entry *ce, const zend_class_constant *trait_constant, zend_string *name
+) {
+	zend_error_noreturn(E_COMPILE_ERROR,
+		"Cannot use trait %s, because constant %s conflicts with enum case %s::%s",
+		ZSTR_VAL(trait_constant->ce->name),
+		ZSTR_VAL(name),
+		ZSTR_VAL(ce->name),
+		ZSTR_VAL(name)
+	);
+}
+
 static bool do_trait_constant_check(
 	zend_class_entry *ce, zend_class_constant *trait_constant, zend_string *name, zend_class_entry **traits, size_t current_trait
 ) {
@@ -2771,7 +2783,7 @@ static bool do_trait_constant_check(
 	zend_class_constant *existing_constant = Z_PTR_P(zv);
 
 	if (UNEXPECTED(ZEND_CLASS_CONST_FLAGS(existing_constant) & ZEND_CLASS_CONST_IS_CASE)) {
-		emit_incompatible_trait_constant_error(ce, existing_constant, trait_constant, name, traits, current_trait);
+		emit_trait_constant_enum_case_conflict_error(ce, trait_constant, name);
 		return false;
 	}