On Windows, inline environment variable values case-insensitively

[jansorg]

On Windows, when inlining environment variable values, e.g. $PATH$ and $Path should both refer to the same value.
On macOS and Linux, names of environment variables are case-sensitive and must be treated as before.

On Windows, this prints second:

set myVALUE=first
set MYvalue=second
echo %myvalue%