CppLanguageServer: Work with a HashMap of Symbols in each document

This is a pretty fundamental refactor of the way
CppComprehensionEngine works.

Previously, in order to answer queries such as "goto definition" or
"autocomplete", we would do ad-hoc logic of walking the AST,
collecting available declaration nodes, computing scopes, and so on.

This commit introduces an architectural change where each Document
builds a hashmap of symbols on creation.

With these hashmaps, it's easier to iterate over all of the available
symbols, and to answer a query such as "which symbols are defined in
this scope".

0 files changed, 0 insertions, 0 deletions