dev-lang/spidermonkey: Fix bug 325849 , fixing compilation on hardened and portage-multilib by replacing a call to $(LD) with a call to $(CC) and ensuring that CFLAGS and LDFLAGS are both respected.

(Portage version: 2.2.0_alpha11-r1/hg/Linux x86_64, signed Manifest commit with key 6BA81050)