port-amd64/55636: bootx64.efi.so.tmp: error: PHDR segment not covered by LOAD segment

[gson%gson.org@localhost (Andreas Gustafsson)]

>Number:         55636
>Category:       port-amd64
>Synopsis:       bootx64.efi.so.tmp: error: PHDR segment not covered by LOAD segment
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    port-amd64-maintainer
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Tue Sep 01 18:05:00 +0000 2020
>Originator:     Andreas Gustafsson
>Release:        NetBSD-current
>Organization:
>Environment:
System: NetBSD
Architecture: x86_64
Machine: amd64
>Description:

Build logs from amd64 release builds contain error messages like
these:

  /tmp/build/2020.09.01.04.19.16-amd64/tools/bin/x86_64--netbsd-ld: bootx64.efi.so.tmp: error: PHDR segment not covered by LOAD segment

There is also a similar message regarding bootia32.efi.so.tmp.

The ld process is exiting with an exit status of zerodespite the
error, so the build continues and ultimately succeeds.

I don't know if this is actually breaking something, or is expected
and harmless but wrongly labeled as an error rather than a warning,
but I figure it's a bug either way.  And either way, it's making it
more difficult to locate actual build errors in the log by looking for
the string "error:".

>How-To-Repeat:

Build NetBSD-current/amd64.  Inspect the messages printed.

>Fix: