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/semgnrc.nim

@@ -481,7 +481,7 @@ proc semGenericStmt(c: PContext, n: PNode,
       if sfGenSym in s.flags and s.ast == nil:
         body = n[bodyPos]
       else:
-        body = s.getBody
+        body = getBody(c.graph, s)
     else: body = n[bodyPos]
     n[bodyPos] = semGenericStmtScope(c, body, flags, ctx)
     closeScope(c)