Well, my assembler worked, I think:

3c 60 0f b4     lis     r3, file@hi
60 63 68 e4     ori     r3, r3, file@lo
38 80 00 3a     li      r4, line
3d 40 0f 6e     lis     r10, report_unimplemented@hi
61 4a 82 60     ori     r10, r10, report_unimplemented@lo
7d 48 03 a6     mtlr    r10
4e 80 00 21     blrl
3d 40 0f e5     lis     r10, abort@hi
61 4a 7b a0     ori     r10, r10, abort@lo
7d 48 03 a6     mtlr    r10
4e 80 00 21     blrl