t4030, t4031: work around bogus MSYS bash path conversion

t4030, t4031: work around bogus MSYS bash path conversion

Recall that MSYS bash converts POSIX style absolute paths to Windows style
absolute paths. Unfortunately, it converts a program argument that begins
with a double-quote and otherwise looks like an absolute POSIX path, but
in doing so, it strips everything past the second double-quote[*]. This
case is triggered in the two test scripts. The work-around is to place the
Windows style path returned by $(pwd) between the quotes to avoid the path
conversion.

[*] It is already bogus that a conversion is even considered when a program
argument begins with a double-quote because it cannot be an absolute POSIX
path.

Signed-off-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>