Test scripts have been updated to remove assumptions that are not
portable between Git for POSIX and Git for Windows, or to skip ones
with expectations that are not satisfiable on Git for Windows.

* js/mingw-tests: (21 commits)
  gitignore: ignore generated test-fake-ssh executable
  mingw: do not bother to test funny file names
  mingw: skip a test in t9130 that cannot pass on Windows
  mingw: handle the missing POSIXPERM prereq in t9124
  mingw: avoid illegal filename in t9118
  mingw: mark t9100's test cases with appropriate prereqs
  t0008: avoid absolute path
  mingw: work around pwd issues in the tests
  mingw: fix t9700's assumption about directory separators
  mingw: skip test in t1508 that fails due to path conversion
  tests: turn off git-daemon tests if FIFOs are not available
  mingw: disable mkfifo-based tests
  mingw: accomodate t0060-path-utils for MSYS2
  mingw: fix t5601-clone.sh
  mingw: let lstat() fail with errno == ENOTDIR when appropriate
  mingw: try to delete target directory before renaming
  mingw: prepare the TMPDIR environment variable for shell scripts
  mingw: factor out Windows specific environment setup
  Git.pm: stop assuming that absolute paths start with a slash
  mingw: do not trust MSYS2's MinGW gettext.sh
  ...