- Use TokenDescriptor instead of intptr_t for all token positions.
- Use TokenDescriptor in raw_object instead of int32_t.
- TokenDescriptor is a POD with an int32_t (this shrinks the size of AST and IR nodes by 32-bits on 64-bit architectures).
There are some cleanups I plan on doing as a follow up CL:
- Replace TokenDescriptor::value() with TokenDescriptor::TokenPos()
R=iposva@google.com, rmacnak@google.com
Review URL: https://codereview.chromium.org/1644793002 .