move assertions out of system (#19599)

compiler/ic/bitabs.nim

@@ -3,6 +3,9 @@
 
 import hashes, rodfiles
 
+when defined(nimPreviewSlimSystem):
+  import std/assertions
+
 type
   LitId* = distinct uint32
 

compiler/ic/cbackend.nim

@@ -20,6 +20,9 @@
 
 import std/packedsets, algorithm, tables
 
+when defined(nimPreviewSlimSystem):
+  import std/assertions
+
 import ".."/[ast, options, lineinfos, modulegraphs, cgendata, cgen,
   pathutils, extccomp, msgs]
 

compiler/ic/dce.nim

@@ -10,6 +10,10 @@
 ## Dead code elimination (=DCE) for IC.
 
 import std/[intsets, tables]
+
+when defined(nimPreviewSlimSystem):
+  import std/assertions
+
 import ".." / [ast, options, lineinfos, types]
 
 import packed_ast, ic, bitabs

compiler/ic/ic.nim

@@ -14,6 +14,9 @@ import ".." / [ast, idents, lineinfos, msgs, ropes, options,
 #import ".." / [renderer, astalgo]
 from os import removeFile, isAbsolute
 
+when defined(nimPreviewSlimSystem):
+  import std/[syncio, assertions]
+
 type
   PackedConfig* = object
     backend: TBackend

compiler/ic/integrity.nim

@@ -11,6 +11,10 @@
 ## The set must cover a complete Nim project.
 
 import sets
+
+when defined(nimPreviewSlimSystem):
+  import std/assertions
+
 import ".." / [ast, modulegraphs]
 import packed_ast, bitabs, ic
 

compiler/ic/navigator.nim

@@ -16,6 +16,9 @@ import sets
 from os import nil
 from std/private/miscdollars import toLocation
 
+when defined(nimPreviewSlimSystem):
+  import std/assertions
+
 import ".." / [ast, modulegraphs, msgs, options]
 import packed_ast, bitabs, ic
 

compiler/ic/packed_ast.nim

@@ -16,6 +16,9 @@ import hashes, tables, strtabs
 import bitabs
 import ".." / [ast, options]
 
+when defined(nimPreviewSlimSystem):
+  import std/assertions
+
 type
   SymId* = distinct int32
   ModuleId* = distinct int32

compiler/ic/replayer.nim

@@ -16,6 +16,9 @@ import ".." / [ast, modulegraphs, trees, extccomp, btrees,
 
 import tables
 
+when defined(nimPreviewSlimSystem):
+  import std/assertions
+
 import packed_ast, ic, bitabs
 
 proc replayStateChanges*(module: PSym; g: ModuleGraph) =

compiler/ic/rodfiles.nim

@@ -16,6 +16,9 @@
 
 from typetraits import supportsCopyMem
 
+when defined(nimPreviewSlimSystem):
+  import std/[syncio, assertions]
+
 ## Overview
 ## ========
 ## `RodFile` represents a Rod File (versioned binary format), and the