Comment 8 for bug 1620754

Dump of assembler code for function siphash24:
   0x000d40a0 <+0>: stmdb sp!, {r4, r5, r6, r7, r8, r9, r10, r11, lr}
   0x000d40a4 <+4>: movw r3, #64168 ; 0xfaa8
   0x000d40a8 <+8>: sub sp, #156 ; 0x9c
   0x000d40aa <+10>: movt r3, #48 ; 0x30
   0x000d40ae <+14>: movw r4, #3232 ; 0xca0
   0x000d40b2 <+18>: movt r4, #51 ; 0x33
   0x000d40b6 <+22>: mov lr, r1
   0x000d40b8 <+24>: str r3, [sp, #124] ; 0x7c
   0x000d40ba <+26>: ldrd r10, r11, [r4]
   0x000d40be <+30>: cmp.w lr, #7
   0x000d40c2 <+34>: ldr r1, [r3, #0]
   0x000d40c4 <+36>: mov.w r3, lr, lsl #24
   0x000d40c8 <+40>: str r3, [sp, #116] ; 0x74
   0x000d40ca <+42>: addw r3, pc, #1564 ; 0x61c
   0x000d40ce <+46>: ldrd r2, r3, [r3]
   0x000d40d2 <+50>: ldrd r8, r9, [r4, #8]
   0x000d40d6 <+54>: eor.w r5, r11, r3
   0x000d40da <+58>: eor.w r4, r10, r2
   0x000d40de <+62>: addw r7, pc, #1552 ; 0x610
   0x000d40e2 <+66>: ldrd r6, r7, [r7]
   0x000d40e6 <+70>: mov.w r3, #0
   0x000d40ea <+74>: strd r4, r5, [sp]
   0x000d40ee <+78>: str r3, [sp, #112] ; 0x70
   0x000d40f0 <+80>: eor.w r6, r6, r10
   0x000d40f4 <+84>: addw r5, pc, #1536 ; 0x600
   0x000d40f8 <+88>: ldrd r4, r5, [r5]
   0x000d40fc <+92>: eor.w r7, r7, r11
   0x000d4100 <+96>: addw r3, pc, #1532 ; 0x5fc
   0x000d4104 <+100>: ldrd r2, r3, [r3]
   0x000d4108 <+104>: str r0, [sp, #128] ; 0x80
   0x000d410a <+106>: eor.w r4, r4, r8
   0x000d410e <+110>: str r1, [sp, #148] ; 0x94
   0x000d4110 <+112>: eor.w r5, r5, r9
   0x000d4114 <+116>: eor.w r2, r2, r8
   0x000d4118 <+120>: eor.w r3, r3, r9
   0x000d411c <+124>: ble.w 0xd42be <siphash24+542>
   0x000d4120 <+128>: sub.w r1, lr, #8
   0x000d4124 <+132>: str r1, [sp, #120] ; 0x78
   0x000d4126 <+134>: mov r12, r0
   0x000d4128 <+136>: lsrs r1, r1, #3
   0x000d412a <+138>: str r1, [sp, #132] ; 0x84
   0x000d412c <+140>: add.w r10, r1, #1
   0x000d4130 <+144>: add.w r10, r0, r10, lsl #3
   0x000d4134 <+148>: str.w r10, [sp, #108] ; 0x6c
=> 0x000d4138 <+152>: ldrd r10, r11, [r12], #8