Don't run a few tests which fail on XP

repl tests freeze otherwise, the fix in libuv for #7082 does not work on XP

dllist tests also fail on xp since oddly Libdl.dllist()
is only listing file names, not full absolute paths

udp recvfrom tests give ERROR: LoadError: bind: address family not supported (EAFNOSUPPORT)

test/backtrace.jl

@@ -16,8 +16,8 @@ end
 dlls = Libdl.dllist()
 @test !isempty(dlls)
 @test length(dlls) > 3 # at a bare minimum, probably have some version of libstdc, libgcc, libjulia, ...
-@test Base.samefile(Libdl.dlpath(dlls[1]), dlls[1])
-@test Base.samefile(Libdl.dlpath(dlls[end]), dlls[end])
+@non_windowsxp_only @test Base.samefile(Libdl.dlpath(dlls[1]), dlls[1])
+@non_windowsxp_only @test Base.samefile(Libdl.dlpath(dlls[end]), dlls[end])
 @test length(filter(dlls) do dl
  return ismatch(Regex("^libjulia(?:.*)\.$(Libdl.dlext)(?:\..+)?\$"), basename(dl))
  end) == 1 # look for something libjulia-like (but only one)

test/repl.jl

@@ -25,7 +25,7 @@ ccall(:jl_exit_on_sigint, Void, (Cint,), 0)
 # in the mix. If verification needs to be done, keep it to the bare minimum. Basically
 # this should make sure nothing crashes without depending on how exactly the control
 # characters are being used.
-begin
+@non_windowsxp_only begin
 stdin_write, stdout_read, stdout_read, repl = fake_repl()
 
 repl.specialdisplay = Base.REPL.REPLDisplay(repl)
@@ -235,7 +235,7 @@ end
 
 ccall(:jl_exit_on_sigint, Void, (Cint,), 1)
 
-let exename = joinpath(JULIA_HOME, Base.julia_exename())
+@non_windowsxp_only let exename = joinpath(JULIA_HOME, Base.julia_exename())
 
 # Test REPL in dumb mode
 @unix_only begin

test/socket.jl

@@ -159,7 +159,7 @@ begin
  close(a)
  close(b)
 end
-begin
+@non_windowsxp_only begin
  a = UDPSocket()
  b = UDPSocket()
  bind(a, ip"::1", UInt16(port))