test-histedit: $TESTTMP quoting fixes for Windows
Without this, C:\path\to\test is converted into C:pathtotest.
Since $TESTTMP appears in output, seems to work in some places without quotes,
and is also used within a larger quote block (see test-rebase-collapse.t, ~line
160), I'm not sure what a check-code rule would look like (or even if it is
feasible).
$ hg init
$ echo a > a
$ hg ci -Am t
adding a
$ hg mv a b
$ hg ci -Am t1
$ hg debugrename b
b renamed from a:b789fdd96dc2f3bd229c1dd8eedf0fc60e2b68e3
$ hg mv b a
$ hg ci -Am t2
$ hg debugrename a
a renamed from b:37d9b5d994eab34eda9c16b195ace52c7b129980
$ hg debugrename --rev 1 b
b renamed from a:b789fdd96dc2f3bd229c1dd8eedf0fc60e2b68e3