test-casefolding: fix wrong case on hfs on linux
on linux hfs keeps the old case of the file stored
force it by renameing to another name and back
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
removing b
created new head
% should abort
abort: crosses branches (use 'hg merge' or 'hg update -C' to discard changes)
% should succeed
abort: crosses branches (use 'hg merge' or 'hg update -C')