remove the last global variables in the C code generator

compiler/cgendata.nim

@@ -119,6 +119,17 @@ type
     graph*: ModuleGraph
     strVersion*, seqVersion*: int # version of the string/seq implementation to use
 
+    nimtv*: Rope            # Nim thread vars; the struct body
+    nimtvDeps*: seq[PType]  # type deps: every module needs whole struct
+    nimtvDeclared*: IntSet  # so that every var/field exists only once
+                            # in the struct
+                            # 'nimtv' is incredibly hard to modularize! Best
+                            # effort is to store all thread vars in a ROD
+                            # section and with their type deps and load them
+                            # unconditionally...
+                            # nimtvDeps is VERY hard to cache because it's
+                            # not a list of IDs nor can it be made to be one.
+
   TCGen = object of TPassContext # represents a C source file
     s*: TCFileSections        # sections of the C file
     flags*: set[Codegenflag]
@@ -177,7 +188,7 @@ proc newProc*(prc: PSym, module: BModule): BProc =
 
 proc newModuleList*(g: ModuleGraph): BModuleList =
   BModuleList(modules: @[], typeInfoMarker: initTable[SigHash, Rope](), config: g.config,
-    graph: g)
+    graph: g, nimtvDeps: @[], nimtvDeclared: initIntSet())
 
 iterator cgenModules*(g: BModuleList): BModule =
   for i in 0..high(g.modules):