Remove many false positives with make checkdpadd

- Reduce DPADD and LDADD in checkdpadd to -l<foo>
- Skip over -Wl,[es]*-group because -Wl,--end-group and
  -Wl,--start-group might be required to properly link objects (see
  usr.bin/clang/lldb as an example)

This caveat has been present for a while with some components of
the build. However, these false positives were made more more apparent
after r269648.

Phabric: D635
Reviewed by: jmmv (an earlier version)
PR: 192730
MFC after: 2 weeks

share/mk/bsd.dep.mk

@@ -215,8 +215,10 @@ cleandepend:
 .endif
 
 .if !target(checkdpadd) && (defined(DPADD) || defined(LDADD))
-_LDADD_FROM_DPADD=	${DPADD:C;^/usr/lib/lib(.*)\.a$;-l\1;}
-_LDADD_CANONICALIZED=	${LDADD:S/$//}
+_LDADD_FROM_DPADD=	${DPADD:R:T:C;^lib(.*)$;-l\1;g}
+# Ignore -Wl,--start-group/-Wl,--end-group as it might be required in the
+# LDADD list due to unresolved symbols
+_LDADD_CANONICALIZED=	${LDADD:N:R:T:C;^lib(.*)$;-l\1;g:N-Wl,--[es]*-group}
 checkdpadd:
 .if ${_LDADD_FROM_DPADD} != ${_LDADD_CANONICALIZED}
 	@echo ${.CURDIR}