* prelude.rb: added. run this script on startup.

* tool/compile_prelude.rb: compile prelude.rb to C string.
  (prelude.rb -> prelude.c)
* common.mk: fix to build with prelude.c.
* inits.c (rb_call_inits): ditto.
* thread.c (Init_Thread): move definition of Mutex#synchronize
  to prelude.rb.



git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@13247 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

prelude.rb

@@ -0,0 +1,14 @@
+
+# Mutex
+
+class Mutex
+  class Mutex
+    def synchronize
+      self.lock
+      yield
+    ensure
+      self.unlock
+    end
+  end
+end
+