Implemented return keyword

src/build/Function.go

@@ -34,6 +34,13 @@ func (f *Function) Compile() {
 			continue
 		}
 
+		if line[0].Kind == token.Keyword {
+			switch line[0].Text() {
+			case "return":
+				f.Assembler.Return()
+			}
+		}
+
 		if line[0].Kind == token.Identifier && line[0].Text() == "syscall" {
 			paramTokens := line[2 : len(line)-1]
 			start := 0