Remove expr/stmt (#5857)

tests/generics/tgeneric3.nim

@@ -66,7 +66,7 @@ proc setItem[T,D](Akey: T, Avalue: D, ANode: PNode[T,D]): ref TItem[T,D] {.inlin
 proc cmp[T:int8|int16|int32|int64|int] (a,b: T): T {.inline.} =
   return a-b
 
-template binSearchImpl *(docmp: expr) {.immediate.} =
+template binSearchImpl *(docmp: untyped) =
   var bFound = false
   result = 0
   var H = haystack.len - 1

tests/generics/tgenerictmpl.nim

@@ -5,7 +5,7 @@ discard """
 
 # bug #3498
 
-template defaultOf[T](t: T): expr = (var d: T; d)
+template defaultOf[T](t: T): untyped = (var d: T; d)
 
 echo defaultOf(1) #<- excpected 0
 

tests/generics/tgenerictmpl2.nim

@@ -27,5 +27,5 @@ ttmpl[int]    #<- crash case #3
 
 # but still allow normal use of [] on non-generic templates
 
-template tarr: expr = [1, 2, 3, 4]
+template tarr: untyped = [1, 2, 3, 4]
 echo tarr[1]

tests/generics/tunique_type.nim

@@ -36,7 +36,7 @@ proc derefExpr(exprRef: string): NimNode {.compileTime.} =
 type Mapped[Input; predicate: static[string]] = object
   input: Input
 
-macro map(input, predicate: expr): expr =
+macro map(input, predicate: untyped): untyped =
   let predicate = callsite()[2]
   newNimNode(nnkObjConstr).add(
     newNimNode(nnkBracketExpr).add(
@@ -47,7 +47,7 @@ macro map(input, predicate: expr): expr =
       ident"input", input))
 
 proc `[]`(m: Mapped, i: int): auto =
-  macro buildResult: expr =
+  macro buildResult: untyped =
     newCall(
       derefExpr(m.predicate),
       newNimNode(nnkBracketExpr).add(