* Correct the function prototypes for some of the functions to match the

  actual spec (int -> uint)
* Add the ability to get/cache the strlen function prototype.
* Make sure generated values are appropriately named for debugging purposes
* Add the SPrintFOptimiation for 4 casts of sprintf optimization:
    sprintf(str,cstr) -> llvm.memcpy(str,cstr) (if cstr has no %)
    sprintf(str,"")   -> store sbyte 0, str
    sprintf(str,"%s",src) -> llvm.memcpy(str,src) (if src is constant)
    sprintf(str,"%c",chr) -> store chr, str   ; store sbyte 0, str+1

The sprintf optimization didn't fire as much as I had hoped:

  2 MultiSource/Applications/SPASS
  5 MultiSource/Benchmarks/McCat/18-imp
 22 MultiSource/Benchmarks/Prolangs-C/TimberWolfMC
  1 MultiSource/Benchmarks/Prolangs-C/assembler
  6 MultiSource/Benchmarks/Prolangs-C/unix-smail
  2 MultiSource/Benchmarks/mediabench/mpeg2/mpeg2dec

llvm-svn: 21679