switch should be nimOldShiftRight with the nim prefix

changelog.md

@@ -46,7 +46,7 @@
 - A bug allowed `macro foo(): int = 123` to compile even though a
   macros has to return a `NimNode`. This has been fixed.
 
-- `shr` is now sign preserving. Use `-d:oldShiftRight` to enable old
+- `shr` is now sign preserving. Use `-d:nimOldShiftRight` to enable old
   behavior globally.
 
 - With the exception of `uint` and `uint64`, conversion to unsigned types

config/nim.cfg

@@ -278,5 +278,5 @@ tcc.options.always = "-w"
   --multimethods:on
   --oldAst:on
   --define:nimOldCaseObjects
-  --define:oldShiftRight
+  --define:nimOldShiftRight
 @end

lib/system.nim

@@ -1271,7 +1271,7 @@ else:
 
 when defined(nimNewShiftOps):
 
-  when defined(oldShiftRight) or not defined(nimAshr):
+  when defined(nimOldShiftRight) or not defined(nimAshr):
     const shrDepMessage = "`shr` will become sign preserving."
     proc `shr`*(x: int, y: SomeInteger): int {.magic: "ShrI", noSideEffect, deprecated: shrDepMessage.}
     proc `shr`*(x: int8, y: SomeInteger): int8 {.magic: "ShrI", noSideEffect, deprecated: shrDepMessage.}