- C function types and Cminor signatures annotated by calling conventions.
  esp. vararg / not vararg
- Cshmgen: generate correct code for function call where there are
  more arguments than listed in the function prototype.  This is
  still undefined behavior according to the formal semantics,
  but correct code is generated.
- C2C, */PrintAsm.ml: remove "printf$iif" hack.
- powerpc/, checklink/: don't generate stubs for variadic functions.


git-svn-id: https://yquem.inria.fr/compcert/svn/compcert/trunk@2386 fca1b0fc-160b-0410-b1d3-a4f43f01ea2e