IC: next steps (#16550)

* cleanups
* ast.nim: cleanups
* IC: no more sym.tab field, stored externally in the module graph
* nimble compiles again
* rodfiles: store bitwidth of integers and the endianness in the cookie because we serialize 'int' directly
* rodfiles: added compilerproc and export sections
* rodfiles: added all the missing sections
* rodfiles: track the missing information
* IC: architecture for lazy loading of proc bodies
* make tests green again
* completed the lazy loading of proc bodies
* symbol lookup integration, part 1
* symbol lookup integration, part 2
* symbol lookup integration, part 3
* make tcompilerapi work again
* rodfiles: fixed config change handling

compiler/evaltempl.nim

@@ -187,7 +187,7 @@ proc evalTemplate*(n: PNode, tmpl, genSymOwner: PSym;
   ctx.instID = instID[]
   ctx.idgen = idgen
 
-  let body = tmpl.getBody
+  let body = tmpl.ast[bodyPos]
   #echo "instantion of ", renderTree(body, {renderIds})
   if isAtom(body):
     result = newNodeI(nkPar, body.info)