alloca.c build failures for gcc46, gcc47 and gcc48 on netbsd-6 amd64

[David Brownlee <abs%absd.org@localhost>]

Well, at least the behaviour is consistent between all three - this is
with the very latest netbsd-6 branch on amd64.

Is anyone else seeing this or similar?

gcc46:
/var/obj/pkg/lang/gcc46/work/gcc-4.6.4/libiberty/alloca.c: In function
'C_alloca':
/var/obj/pkg/lang/gcc46/work/gcc-4.6.4/libiberty/alloca.c:200:5:
warning: implicit declaration of function 'XNEWVEC'
[-Wimplicit-function-declaration]
/var/obj/pkg/lang/gcc46/work/gcc-4.6.4/libiberty/alloca.c:200:43:
error: expected expression before 'char'

gcc47:
../../gcc-4.7.3/libiberty/alloca.c: In function 'C_alloca':
../../gcc-4.7.3/libiberty/alloca.c:200:5: warning: implicit
declaration of function 'XNEWVEC' [-Wimplicit-function-declaration]
../../gcc-4.7.3/libiberty/alloca.c:200:43: error: expected expression
before 'char'

gcc48:
../../gcc-4.8.3/libiberty/alloca.c: In function 'C_alloca':
../../gcc-4.8.3/libiberty/alloca.c:200:5: warning: implicit
declaration of function 'XNEWVEC' [-Wimplicit-function-declaration]
     register void *new_storage = XNEWVEC (char, sizeof (header) + size);
     ^
../../gcc-4.8.3/libiberty/alloca.c:200:43: error: expected expression
before 'char'
     register void *new_storage = XNEWVEC (char, sizeof (header) + size);