If the last BPF instruction before exit is a ldimm64, branches to the
exit point at the wrong location.

Here is what I get from test_pkt_access.c on sparc:

0000000000000000 <process>:
   0:   b7 00 00 00 00 00 00 02         mov     r0, 2
   8:   61 21 00 50 00 00 00 00         ldw     r2, [r1+80]
  10:   61 11 00 4c 00 00 00 00         ldw     r1, [r1+76]
  18:   bf 41 00 00 00 00 00 00         mov     r4, r1
  20:   07 40 00 00 00 00 00 0e         add     r4, 14
  28:   2d 42 00 25 00 00 00 00         jgt     r4, r2, 148 <LBB0_11>
 ...
0000000000000148 <LBB0_11>:
 148:   18 00 00 00 ff ff ff ff         ldimm64 r0, 4294967295
 150:   00 00 00 00 00 00 00 00 

0000000000000158 <LBB0_12>:
 158:   95 00 00 00 00 00 00 00         exit    

The offset field in the "jgt" instruction is 0x25 which multiplied by
8 is 0x128, add 0x128 to the instruction location which is 0x28, and
we get 0x150, which is the second 64-bit chunk of the ldimm64
instruction.

At least this is what my JIT is interpreting this situation as, am I
off by one or something?

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