fix access to identifiers that are reserved keywords

modules/gdscript/gdscript_parser.cpp

@@ -2820,6 +2820,9 @@ GDScriptParser::ExpressionNode *GDScriptParser::parse_attribute(ExpressionNode *
 
 	attribute->base = p_previous_operand;
 
+	if (current.is_node_name()) {
+		current.type = GDScriptTokenizer::Token::IDENTIFIER;
+	}
 	if (!consume(GDScriptTokenizer::Token::IDENTIFIER, R"(Expected identifier after "." for attribute access.)")) {
 		complete_extents(attribute);
 		return attribute;

modules/gdscript/tests/scripts/parser/features/reserved_keywords_as_attribute.gd

@@ -0,0 +1,36 @@
+var dict = {}
+
+func test():
+	dict.if = 1
+	dict.elif = 1
+	dict.else = 1
+	dict.for = 1
+	dict.while = 1
+	dict.match = 1
+	dict.break = 1
+	dict.continue = 1
+	dict.pass = 1
+	dict.return = 1
+	dict.class = 1
+	dict.class_name = 1
+	dict.extends = 1
+	dict.is = 1
+	dict.in = 1
+	dict.as = 1
+	dict.self = 1
+	dict.signal = 1
+	dict.func = 1
+	dict.static = 1
+	dict.const = 1
+	dict.enum = 1
+	dict.var = 1
+	dict.breakpoint = 1
+	dict.preload = 1
+	dict.await = 1
+	dict.yield = 1
+	dict.assert = 1
+	dict.void = 1
+	dict.PI = 1
+	dict.TAU = 1
+	dict.INF = 1
+	dict.NAN = 1

modules/gdscript/tests/scripts/parser/features/reserved_keywords_as_attribute.out

@@ -0,0 +1 @@
+GDTEST_OK