**TODO**
- [x] fixes changelog
With the new option `nimPreviewVtables`, `methods` are confined in the
same module where the type of the first parameter is defined
- [x] make it opt in after CI checks its feasibility
## In the following-up PRs
- [ ] in the following PRs, refactor code into a more efficient one
- [ ] cpp needs special treatments since it cannot embed array in light
of the preceding limits: ref
https://github.com/nim-lang/Nim/pull/20977#discussion_r1035528927; we
can support cpp backends with vtable implementations later on the
comprise that uses indirect vtable access
---------
Co-authored-by: Andreas Rumpf <rumpf_a@web.de>
* IC: renamed to_packed_ast module to ic module
* IC: don't store the --forceBuild flag, makes it easier to test
* IC: enable hello world test
* Codegen: refactorings for IC; changed the name mangling algorithm
* fixed the HCR regressions
* life is too short for HCR
* tconvexhull is now allowed to use deepCopy
* IC exposed a stdlib bug, required a refactoring
* codegen: code cleanups
* IC: even if a module is outdated, its dependencies might come from disk
* IC: progress
* IC: better name mangling, module IDs are not stable
* IC: another refactoring helping with --ic:on --gc:arc
* disable arraymancer on Windows for the time being
* disable arraymancer altogether
* IC: make basic test work with 'nim cpp'
* IC: progress on --ic:on --gc:arc
* wip; name mangling for type info
* IC: compilerprocs are handled correctly
* IC: special logic for .exportC'ed procs
* IC: 'hello world' compiles for the first round (2nd round fails)
* IC: hello world seems to work
* minor improvements
* IC: added the required logic for compilerProcs
* LazySym ftw
* we need this testing logic
* reimplement the old way we use for module package creation
* fixes a regression; don't pick module names if you can avoid it
* removed dead code
* we need even more laziness for the generic caches
* make it bootstrap on older Nims
* wrote more deserialization code
* IC: replay required methods information
* removed dead code
* beginnings of a rodfile reader
* IC: record global VM state changes and pragma state changes
* IC: replay pragmas and VM state changes
* implemented rod load file simuation for easier, extensive testing
* critical bugfix
* IC: stress test logic; should also help with recursive module dependencies; WIP
* IC: loading from .rod files begins to work reliably
* removed ugly hacks
* yet another silly mistake
