* use a pool of MBState structures to speedup monoburg instead of using a
  mempool.
* the decode tables in the burg-generated could use short instead of int
  (this should save about 1 KB)
* track the use of ESP, so that we can avoid the x86_lea in the epilog


Other Ideas:

* the ORP people avoids optimizations inside catch handlers - just to save
  memory (for example allocation of strings - instead they allocate strings when
  the code is executed (like the --shared option)). But there are only a few
  functions using catch handlers, so I consider this a minor issue.

* some performance critical functions should be inlined. These include:
	- mono_mempool_alloc and mono_mempool_alloc0
	- EnterCriticalSection and LeaveCriticalSection
	- TlsSetValue
	- mono_metadata_row_col
	- mono_g_hash_table_lookup
	- mono_domain_get
* the managed/unmanaged boundary is quite slow:
	- it calls mono_get_lmf_addr, which calls TlsGetValue, which calls
      pthread_getspecific (). This means that 3 function calls are needed for
      each native function call.

* if a function which involves locking is called from another function which
  acquires the same lock, it might be useful to create a separate _inner 
  version of the function which does not re-acquire the lock. This is a perf
  win only if the function is called a lot of times, like mono_get_method.

* the frame_state_for function in glibc 2.3.2 can't correctly decipher the 
  unwind tables generated by gcc 3.3. It allways tells the runtime that not all
  callee saved registers are saved, even when the icall is marked with
  MONO_ARCH_SAVE_REGS. This forces the runtime to generate wrapper functions
  for all icalls, slowing things down greatly.

* we can avoid calls to class init trampolines if the are multiple calls to the
  same trampoline in the same basic block. See:

  http://bugzilla.ximian.com/show_bug.cgi?id=51096

Usability
---------

* Remove the various optimization list of flags description, have an 
  extra --help-optimizations flag.

* Remove the various graph options, have a separate --help-graph for 
  that list.