IC: green tests (#17311)

* 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* IC: even if a module is outdated, its dependencies might come from disk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

lib/system/excpt.nim

@@ -567,7 +567,7 @@ when defined(cpp) and appType != "lib" and not gotoBasedExceptions and
   type
     StdException {.importcpp: "std::exception", header: "<exception>".} = object
 
-  proc what(ex: StdException): cstring {.importcpp: "((char *)#.what())".}
+  proc what(ex: StdException): cstring {.importcpp: "((char *)#.what())", nodecl.}
 
   proc setTerminate(handler: proc() {.noconv.})
     {.importc: "std::set_terminate", header: "<exception>".}