krb5, kerberos5: Remove no-undefined linker option

[cy]

Summary

krb5 build failures started occuring recently. This commit fixes
libc symbols not being resolved.

--no-undefined is not needed, let's remove it.

This affects both the legacy Heimdal and the recent MIT KRB5.

Test Plan

Running it here.

[emaste]

krb5 build failures have been occurring for a while afaik, e.g. PR293258? 9cea0f0be79d should be a no-op since the now-removed (portions of) if conditions were always true .if ${${X_}LINKER_TYPE} != "bfd" || ${${X_}LINKER_VERSION} > 21750 and the part of .if ${${X_}LINKER_TYPE} == "bfd" && ${${X_}LINKER_VERSION} > 21750 after &&

[cy]

In D55678#1274214, @emaste wrote:

krb5 build failures have been occurring for a while afaik, e.g. PR293258? 9cea0f0be79d should be a no-op since the now-removed (portions of) if conditions were always true .if ${${X_}LINKER_TYPE} != "bfd" || ${${X_}LINKER_VERSION} > 21750 and the part of .if ${${X_}LINKER_TYPE} == "bfd" && ${${X_}LINKER_VERSION} > 21750 after &&

This is a libc symbols not found problem. PR/293258 is libk5profile.a symbols issue.

[cy]

My Heimdal builds also fail with the same error. Something has recently changed in the tree to cause these two unrelated Kerberosen to fail with the same libc objects not found.

[cy]

This patch only masks another problem. When this patch is applied, usr.bin/ldd32 fails on the same error. The symbols that are exported in lib/libc.so, are not exported in lib32/libc.so. The problem is elsewhere but not here.

Having said that, there is merit in removing --no-undefined. I will resubmit this at a later time.

[emaste]

I observed the same failure with 9cea0f0be79d reverted and am trying to figure out where this came from.

[emaste]

Oh I see @delphij fixed the build in 8dd28e13e41b6200e58d6e99981ff8323cff3711