The problem is newer binutils will no longer default to --copy-dt-needed-entries but use --no-copy-dt-needed-entries instead. So all libraries needed *must* be provided.
Workarounds (either one works)
1) Add "-Wl,--copy-dt-needed-entries" to LDFLAGS to bring back the old behavior of the linker
2) Add "-lz" to list of libraries to be added
In "ext/mysqlnd/mysqlnd_protocol_frame_codec.c" when the "zlib.h" header is included should also trigger adding '-lz' to the list of libraries.