The main idea is to compile the cxx grammar at build time, and construct
the core pieces (Grammar, LRTable) of the pseudoparse based on the compiled
This is a tiny implementation, which is good for start:
- defines how the public API should look like;
- integrates the cxx grammar compilation workflow with the cmake system.
- onlynonterminal symbols of the C++ grammar are compiled, anything else are still doing the real compilation work at runtime, we can opt-in more bits in the future;
- splits the monolithic clangPsuedo library for better layering;