Make WITHOUT_UNDEFINED_VERSION the default

Link with --no-undefined-version by default.  Will detect and prevent
the accidental removal of symbols from versioned libraries.

(cherry picked from commit 4510f2ca91)
This reverts commit b25ceb97ed.

Reviewed by:	arichardson, kib, dim, emaste
Differential Revision:	https://reviews.freebsd.org/D44216

share/man/man5/src.conf.5

@@ -1719,9 +1719,11 @@ and that the runtime support library is available
 Do not build
 .Xr unbound 8
 and related programs.
-.It Va WITHOUT_UNDEFINED_VERSION
+.It Va WITH_UNDEFINED_VERSION
-Link libraries with --no-undefined-version to ensure all symbols are
+Link libraries with --undefined-version which permits version maps to
-provided.
+contain symbols that are not present in the library.
+If this is necessicary to build a particular configuration, a bug is
+present and the configuration should be reported.
 .It Va WITHOUT_UNIFIED_OBJDIR
 Use the historical object directory format for
 .Xr build 7

share/mk/bsd.opts.mk

@@ -68,7 +68,6 @@ __DEFAULT_YES_OPTIONS = \
     SSP \
     TESTS \
     TOOLCHAIN \
-    UNDEFINED_VERSION \
     WARNS \
     WERROR
 
@@ -81,7 +80,8 @@ __DEFAULT_NO_OPTIONS = \
     PROFILE \
     RETPOLINE \
     STALE_STAGED \
-    UBSAN
+    UBSAN \
+    UNDEFINED_VERSION
 
 __DEFAULT_DEPENDENT_OPTIONS = \
     MAKE_CHECK_USE_SANDBOX/TESTS \

tools/build/options/WITHOUT_UNDEFINED_VERSION

@@ -1,2 +0,0 @@
-Link libraries with --no-undefined-version to ensure all symbols are
-provided.

tools/build/options/WITH_UNDEFINED_VERSION

@@ -0,0 +1,4 @@
+Link libraries with --undefined-version which permits version maps to
+contain symbols that are not present in the library.
+If this is necessicary to build a particular configuration, a bug is
+present and the configuration should be reported.