Merge pull request #7771 from nim-lang/nim-in-action-fixes

Higher Nim in Action coverage plus regression fix.

lib/pure/strutils.nim

@@ -17,6 +17,10 @@ import parseutils
 from math import pow, round, floor, log10
 from algorithm import reverse
 
+when defined(nimVmExportFixed):
+  from unicode import toLower, toUpper
+  export toLower, toUpper
+
 {.deadCodeElim: on.}  # dce option deprecated
 
 {.push debugger:off .} # the user does not want to trace a part