Front-end
 - trigraph sequences (??:, ...) ISO 5.2.1.1
 - name spaces for struct/enum/union are the same ISO 6.2.3
 - check integer conversion ISO 6.3.1.1
 - character constants (type, value, escapes) ISO 6.4.4.4
 - string literals (value, escapes) ISO 6.4.5
 - punctuation tokens ISO 6.4.6
 - default argument promotions in function calls ISO 6.5.2.2
 - compound literals ISO 6.5.2.5. Missing fields initialized to 0!!
 - check that long long is properly done in type specs ISO 6.7.2
 - Initialization ISO 6.7.8

- MSVC has a bug in the handling of shift operators: arithmetic
  conversions are applied on both operands instead of just integral
  promotions. We duplicate this bug in doBinOp in cabs2cil.

 - we should allow the user to specify a logging function that takes
   printf()-style arguments (rather than hardcoding syslog/printk/printf).

 - the restrict attribute is dropped in cabs2cil

 - struct and union must share the name space

 - when merging we use too much memory. We should be droping the references to
 the CABS files once we convert each one to CIL.