cleanup nfFirstWrite flags (#20500)

compiler/ast.nim

@@ -509,7 +509,6 @@ type
     nfExecuteOnReload  # A top-level statement that will be executed during reloads
     nfLastRead  # this node is a last read
     nfFirstWrite # this node is a first write
-    nfFirstWrite2 # alternative first write implementation
     nfHasComment # node has a comment
     nfUseDefaultField # node has a default value (object constructor)
 
@@ -1078,7 +1077,7 @@ const
                                       nfIsRef, nfIsPtr, nfPreventCg, nfLL,
                                       nfFromTemplate, nfDefaultRefsParam,
                                       nfExecuteOnReload, nfLastRead,
-                                      nfFirstWrite, nfFirstWrite2}
+                                      nfFirstWrite}
   namePos* = 0
   patternPos* = 1    # empty except for term rewriting macros
   genericParamsPos* = 2

compiler/injectdestructors.nim

@@ -162,7 +162,7 @@ proc isLastRead(n: PNode; c: var Con; s: var Scope): bool =
 
 proc isFirstWrite(n: PNode; c: var Con): bool =
   let m = skipConvDfa(n)
-  result = nfFirstWrite2 in m.flags
+  result = nfFirstWrite in m.flags
 
 proc isCursor(n: PNode): bool =
   case n.kind

compiler/lambdalifting.nim

@@ -249,7 +249,7 @@ proc genCreateEnv(env: PNode): PNode =
   var c = newNodeIT(nkObjConstr, env.info, env.typ)
   c.add newNodeIT(nkType, env.info, env.typ)
   let e = copyTree(env)
-  e.flags.incl nfFirstWrite2
+  e.flags.incl nfFirstWrite
   result = newAsgnStmt(e, c)
 
 proc liftIterSym*(g: ModuleGraph; n: PNode; idgen: IdGenerator; owner: PSym): PNode =

compiler/sempass2.nim

@@ -218,7 +218,7 @@ proc initVar(a: PEffects, n: PNode; volatileCheck: bool) =
       run outside of the while loop. This is why we need the check here that
       the assignment is done in the same logical block as `x` was declared in.
       ]#
-      n.flags.incl nfFirstWrite2
+      n.flags.incl nfFirstWrite
 
 proc initVarViaNew(a: PEffects, n: PNode) =
   if n.kind != nkSym: return

compiler/transf.nim

@@ -107,7 +107,7 @@ proc newAsgnStmt(c: PTransf, kind: TNodeKind, le: PNode, ri: PNode; isFirstWrite
   result = newTransNode(kind, ri.info, 2)
   result[0] = le
   if isFirstWrite:
-    le.flags.incl nfFirstWrite2
+    le.flags.incl nfFirstWrite
   result[1] = ri
 
 proc transformSymAux(c: PTransf, n: PNode): PNode =