Fix phpGH-17469: UConverter::transcode() not hardcoding error handling.

Respecting instead intl.use_exceptions/intl.error_level.

ext/intl/converter/converter.c

@@ -376,25 +376,31 @@ static bool php_converter_set_encoding(php_converter_object *objval,
 			/* Should never happen */
 			actual_encoding = "(unknown)";
 		}
-		php_error_docref(NULL, E_WARNING, "Ambiguous encoding specified, using %s", actual_encoding);
+		char *msg;
+		spprintf(&msg, 0, "Ambigious encoding specified, using %s", actual_encoding);
+		intl_error_set(NULL, error, msg, 1);
+		efree(msg);
 	} else if (U_FAILURE(error)) {
 		if (objval) {
 			THROW_UFAILURE(objval, "ucnv_open", error);
 		} else {
-			php_error_docref(NULL, E_WARNING, "Error setting encoding: %d - %s", (int)error, u_errorName(error));
+			char *msg;
+			spprintf(&msg, 0, "Error setting encoding: %d - %s", (int)error, u_errorName(error));
+			intl_error_set(NULL, error, msg, 1);
+			efree(msg);
 		}
-		return 0;
+		return false;
 	}
 
 	if (objval && !php_converter_set_callbacks(objval, cnv)) {
-		return 0;
+		return false;
 	}
 
 	if (*pcnv) {
 		ucnv_close(*pcnv);
 	}
 	*pcnv = cnv;
-	return 1;
+	return true;
 }
 /* }}} */