Trim remaining expr/stmt from stdlib (#6742)

lib/system.nim

@@ -2763,9 +2763,9 @@ when defined(nimvarargstyped):
     ## pretends to be free of side effects, so that it can be used for debugging
     ## routines marked as `noSideEffect <manual.html#pragmas-nosideeffect-pragma>`_.
 else:
-  proc echo*(x: varargs[expr, `$`]) {.magic: "Echo", tags: [WriteIOEffect],
+  proc echo*(x: varargs[untyped, `$`]) {.magic: "Echo", tags: [WriteIOEffect],
     benign, sideEffect.}
-  proc debugEcho*(x: varargs[expr, `$`]) {.magic: "Echo", noSideEffect,
+  proc debugEcho*(x: varargs[untyped, `$`]) {.magic: "Echo", noSideEffect,
                                              tags: [], raises: [].}
 
 template newException*(exceptn: typedesc, message: string;
@@ -3706,7 +3706,7 @@ proc instantiationInfo*(index = -1, fullPaths = false): tuple[
   ## .. code-block:: nim
   ##   import strutils
   ##
-  ##   template testException(exception, code: expr): stmt =
+  ##   template testException(exception, code: untyped): typed =
   ##     try:
   ##       let pos = instantiationInfo()
   ##       discard(code)
@@ -3844,11 +3844,11 @@ type
 {.deprecated: [PNimrodNode: NimNode].}
 
 when false:
-  template eval*(blk: stmt): stmt =
+  template eval*(blk: typed): typed =
     ## executes a block of code at compile time just as if it was a macro
     ## optionally, the block can return an AST tree that will replace the
     ## eval expression
-    macro payload: stmt {.gensym.} = blk
+    macro payload: typed {.gensym.} = blk
     payload()
 
 when hasAlloc: