Port to LLVM 3.3

Major changes are:
- Switching to llvm-link to build archive files
- Use GetMallocUsage instead of GetTotalMemoryUsage (be aware of bug in
  LLVM 3.3 http://llvm.org/bugs/show_bug.cgi?id=16847)
- intrinsic library functions like memcpy/mov/set use weak linkage to be
  replaced by e.g. uclibc functions
- rewrote linking with library
- enhanced MemoryLimit test case to check if mallocs were successful