track comptime types

[mfield]

Adds some tracking of comptime types.

changes formatting for comptime structs, e.g. HashMap(...) -> HashMap(i32,void). maybe just a preference of mine? but i like seeing it. could easily change the formatter back to ....

fixes:

• repeated use of the same comptime function Allocator usage causes zls inline types to get very confused #1841
• nested generic structs e.g. incorrect completions on nested generic type like std.ArrayList #1392

[mfield]

sorry for the false start. saw something while reading the diff and made a small change last second without re-building :(
new version is passing tests again!

[Techatrix]

The analysis backend has an existing mechanism to resolve comptime function type parameters. See bound_type_params. I would have expected this field to be replaced instead of adding another solution on top of it. Removing bound_type_params will make most of the existing test fail that deal with generic functions which indicates that this PR is failing to handle them.

Also, have you tried to adding the extra properties of BoundScope to ScopeWithHandle instead of adding .bound_scope to Type.Data? If you need to wrap a container with a bound scope, just create a copy of the existing container with extra bound scopes. I tried to test this change myself but could not quite get it to work so there may be a good reason to keep it this way.

I will hold of with additional review comments until the fundamentals are in a good shape. The idea of keeping a stack of bound parameter types is also what I had in mind when thinking about how to resolve #1392.