libffi 3.0.9 fails to build on AIX

[tom honermann]

  Attempting to build libffi 3.0.9 on AIX fails.  I'm trying to build 
64-bit, but I suspect the build would fail in 32-bit as well.  The error 
message is:

source='src/powerpc/aix.S' object='src/powerpc/aix.lo' libtool=yes \
         DEPDIR=.deps depmode=aix /bin/sh ./depcomp \
         /bin/sh ./libtool   --mode=compile xlc_r -DHAVE_CONFIG_H -I.  
-I. -I./include -Iinclude -I./src  -I. -I./include -Iinclude -I./src 
-q64 -qtune=pwr6 -c -o src/powerpc/aix.lo src/powerpc/aix.S
libtool: compile:  xlc_r -DHAVE_CONFIG_H -I. -I. -I./include -Iinclude 
-I./src -I. -I./include -Iinclude -I./src -q64 -qtune=pwr6 -c -M 
src/powerpc/aix.S  -DPIC -o src/powerpc/.libs/aix.o
Assembler:
/tmp/xlcS0_CamUd.s: line 88: 1252-023 The symbol .ffi_prep_args is not 
defined.
/tmp/xlcS0_CamUd.s: line 88: 1252-087 The target of the branch instruction
         must be a relocatable or external expression.

src/powerpc/aix.S is referencing ffi_prep_args without that symbol 
having been defined.  Perhaps aix.S is intending to use the 
ffi_prep_args implementation in src/powerpc/ffi_darwin.c?  (which would 
imply a poor file name choice?)  Or perhaps there is just a missing 
symbol declaration?

Anyone aware of this issue or aware of anyone fixing it outside of the 
libffi distribution?  I don't see any updates in the github repository.

Tom.