Add sections (type, var, let, const, using) support for reorder pragma (#6326)

tests/pragmas/treorder.nim

@@ -0,0 +1,75 @@
+discard """
+output:'''0
+1
+2
+3'''
+"""
+
+import macros
+{.reorder: on .}
+
+echo foo(-1)
+echo callWithFoo(0)
+echo(CA+CD)
+echo useTypes(TA(x:TB(x:1)), 2)
+second(0)
+  
+template callWithFoo(arg: untyped): untyped =
+  foo(arg)
+  
+proc first(i: int): void
+
+proc second(i: int): void =
+  make(first)
+  first(i)
+
+proc useTypes(a: TA, d: TD): int =
+  result = a.x.x+d
+
+type
+  TDoubleCyclic = ref object
+    x: TCyclicA
+    y: TCyclicB
+
+type
+  TCyclicA = ref object
+    x: TDoubleCyclic
+  
+type
+  TCyclicB = ref object
+    x: TDoubleCyclic
+
+const
+  CA = 1
+  CB = CC
+
+type
+  TA = object
+    x: TB
+  TC = type(CC)
+  TD = type(CA)
+
+const
+  CC = 1
+  CD = CB
+
+type
+  TB = object
+    x: TC
+
+proc foo(x: int): int =
+  result = bar(x)
+
+proc bar(x: int): int =
+  result = x+1
+
+macro make(arg: untyped): untyped =
+  ss &= arg.repr
+  ss &= " "
+  discard
+
+proc first(i: int): void =
+  make(second)
+
+static:
+  var ss: string = ""