global values were being referenced, but the GOT was not being set up.
as the GOT is only required for PIC, this issue wasn't caught in the
default configuration.
Change-Id: I8006e53776139362a76f2c80cf9d0f8458602b2f
http://code.google.com/p/webm/issues/detail?id=328
push rbp
mov rbp, rsp
SHADOW_ARGS_TO_STACK 4
+ GET_GOT rbx
push rsi
push rdi
; end prolog
; begin epilog
pop rdi
pop rsi
+ RESTORE_GOT
UNSHADOW_ARGS
pop rbp
ret
push rbp
mov rbp, rsp
SHADOW_ARGS_TO_STACK 4
+ GET_GOT rbx
; end prolog
; write out
movq [rax+rcx ], mm1
; begin epilog
+ RESTORE_GOT
UNSHADOW_ARGS
pop rbp
ret
push rbp
mov rbp, rsp
SHADOW_ARGS_TO_STACK 4
+ GET_GOT rbx
push rsi
push rdi
; end prolog
; begin epilog
pop rdi
pop rsi
+ RESTORE_GOT
UNSHADOW_ARGS
pop rbp
ret