Get rid of getSizeOf, using ConstantExpr::getSizeOf instead.

Get rid of getSizeOf, using ConstantExpr::getSizeOf instead.

do not insert a prototype for malloc of: void* malloc(uint): on 64-bit u
targets this is not correct.  Instead of prototype it as void *malloc(...),
and pass the correct intptr_t through the "...".

Finally, fix Regression/CodeGen/SparcV9/2004-12-13-MallocCrash.ll, by not
forming constantexpr casts from pointer to uint.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@18908 91177308-0d34-0410-b5e6-96231b3b80d8