Add llhttp gem (#1031)

Author: hakanensari

gems/llhttp/0.6/_test/test.rb

@@ -0,0 +1,8 @@
+require "llhttp"
+
+parser = LLHttp::Parser.new(LLHttp::Delegate.new, type: :response)
+parser.reset
+parser << "HTTP/1.1 200 OK\r\n\r\n"
+parser.status_code
+parser.http_major
+parser.http_minor

gems/llhttp/0.6/llhttp.rbs

@@ -0,0 +1,17 @@
+module LLHttp
+  class Error < StandardError
+  end
+
+  class Parser
+    def initialize: (untyped delegate, ?type: Symbol) -> void
+    def reset: () -> void
+    def <<: (String data) -> void
+    def status_code: () -> Integer
+    def http_major: () -> Integer
+    def http_minor: () -> Integer
+  end
+
+  class Delegate
+    def initialize: () -> void
+  end
+end