Implicit function error - Rebuild of the Debian archive with clang

"Implicit function error" build failure(s)
clang 4.0.1

Versions: 2.9 - 3.0 - 3.1 - 3.2 - 3.3 - 3.4 - 3.4.2 - 3.5.0 - 3.6.0 - 3.8.1 - 3.9.1 - 4.0.1 - 5.0 - 6.0 - 8.0.1 - 9.0.1 - 10.0.0 - 11.0.0 - 12.0.1 - 13.0.0

Package	Version	Supposed error message	Full log	Bug report
collectd	5.7.1-1.1	rte_memcpy.h:814:2: error: implicit declaration of function '_mm_alignr_epi8' is invalid in C99 [-Werror,-Wimplicit-function-declaration]	Log	~~758481~~
freetype	2.8-0.2	ttdebug.c:1935:16: error: implicitly declaring library function 'snprintf' with type 'int (char , unsigned long, const char , ...)' [-Werror,-Wimplicit-function-declaration]	Log
smpq	1.6-1	extract.c:73:16: error: implicit declaration of function 'strdup' [-Werror,-Wimplicit-function-declaration]	Log

3 errors

Debian Package rebuild