clean up old codes (#17071)

compiler/guards.nim

@@ -774,12 +774,7 @@ macro `=~`(x: PNode, pat: untyped): bool =
 
   var conds = newTree(nnkBracket)
   m(x, pat, conds)
-  when compiles(nestList(ident"and", conds)):
-    result = nestList(ident"and", conds)
-  #elif declared(macros.toNimIdent):
-  #  result = nestList(toNimIdent"and", conds)
-  else:
-    result = nestList(!"and", conds)
+  result = nestList(ident"and", conds)
 
 proc isMinusOne(n: PNode): bool =
   n.kind in {nkCharLit..nkUInt64Lit} and n.intVal == -1

lib/pure/htmlgen.nim

@@ -113,10 +113,7 @@ proc xmlCheckedTag*(argsList: NimNode, tag: string, optAttr = "", reqAttr = "",
     result.add(newStrLitNode("</"))
     result.add(newStrLitNode(tag))
     result.add(newStrLitNode(">"))
-  when compiles(nestList(ident"&", result)):
-    result = nestList(ident"&", result)
-  else:
-    result = nestList(!"&", result)
+  result = nestList(ident"&", result)
 
 macro a*(e: varargs[untyped]): untyped =
   ## Generates the HTML ``a`` element.

lib/pure/unittest.nim

@@ -686,7 +686,7 @@ macro check*(conditions: untyped): untyped =
             result.printOuts.add getAst(print(argStr, callVar))
           if exp[i].kind == nnkExprEqExpr:
             # ExprEqExpr
-            #   Ident !"v"
+            #   Ident "v"
             #   IntLit 2
             result.check[i] = exp[i][1]
           if exp[i].typeKind notin {ntyTypeDesc}: