Add String.is_valid_unicode_identifier()

- Adds `is_valid_unicode_identifier()`
- Adds `is_valid_ascii_identifier()`
- Deprecates `is_valid_identifier()`
- Renames `validate_identifier()` to `validate_ascii_identifier()`

servers/rendering/rendering_device_binds.cpp

@@ -112,7 +112,7 @@ Error RDShaderFile::parse_versions_from_text(const String &p_text, const String
 				}
 				Vector<String> slices = l.get_slice(";", 0).split("=");
 				String version = slices[0].strip_edges();
-				if (!version.is_valid_identifier()) {
+				if (!version.is_valid_ascii_identifier()) {
 					base_error = "Version names must be valid identifiers, found '" + version + "' instead.";
 					break;
 				}

servers/rendering/shader_preprocessor.cpp

@@ -173,7 +173,7 @@ String ShaderPreprocessor::Tokenizer::get_identifier(bool *r_is_cursor, bool p_s
 	}
 
 	String id = vector_to_string(text);
-	if (!id.is_valid_identifier()) {
+	if (!id.is_valid_ascii_identifier()) {
 		return "";
 	}
 

servers/text_server.cpp

@@ -2165,23 +2165,7 @@ TypedArray<Dictionary> TextServer::_shaped_text_get_ellipsis_glyphs_wrapper(cons
 }
 
 bool TextServer::is_valid_identifier(const String &p_string) const {
-	const char32_t *str = p_string.ptr();
-	int len = p_string.length();
-
-	if (len == 0) {
-		return false; // Empty string.
-	}
-
-	if (!is_unicode_identifier_start(str[0])) {
-		return false;
-	}
-
-	for (int i = 1; i < len; i++) {
-		if (!is_unicode_identifier_continue(str[i])) {
-			return false;
-		}
-	}
-	return true;
+	return p_string.is_valid_unicode_identifier();
 }
 
 bool TextServer::is_valid_letter(uint64_t p_unicode) const {