x/sys/unix: TestMremapPtr failures

[gopherbot]

#!watchflakes
default <- pkg == "golang.org/x/sys/unix" && test == "TestMremapPtr"

Issue created automatically to collect these failures.

Example (log):

=== RUN   TestMremapPtr
    mremap_test.go:67: MremapPtr: cannot allocate memory
--- FAIL: TestMremapPtr (0.00s)

— watchflakes

[gopherbot]

Found new dashboard test flakes for:

#!watchflakes
default <- pkg == "golang.org/x/sys/unix" && test == "TestMremapPtr"

2024-06-25 00:37 x_sys-go1.21-netbsd-arm64 sys@daa23942 release-branch.go1.21@dfb00670 x/sys/unix.TestMremapPtr (log)

=== RUN   TestMremapPtr
    mremap_test.go:67: MremapPtr: cannot allocate memory
--- FAIL: TestMremapPtr (0.00s)

2024-06-25 00:37 x_sys-go1.22-netbsd-arm64 sys@daa23942 release-branch.go1.22@11b861e4 x/sys/unix.TestMremapPtr (log)

=== RUN   TestMremapPtr
    mremap_test.go:67: MremapPtr: cannot allocate memory
--- FAIL: TestMremapPtr (0.00s)

2024-06-25 00:37 x_sys-go1.23-netbsd-arm64 sys@daa23942 release-branch.go1.23@7dff7439 x/sys/unix.TestMremapPtr (log)

=== RUN   TestMremapPtr
    mremap_test.go:67: MremapPtr: cannot allocate memory
--- FAIL: TestMremapPtr (0.00s)

2024-06-25 00:37 x_sys-gotip-netbsd-arm64 sys@daa23942 go@b1fd0475 x/sys/unix.TestMremapPtr (log)

=== RUN   TestMremapPtr
    mremap_test.go:67: MremapPtr: cannot allocate memory
--- FAIL: TestMremapPtr (0.00s)

— watchflakes

[ianlancetaylor]

I believe that these are reoccurrences of #68180 from before the fix was committed.