instruction: 0.557
runtime: 0.329
syscall: 0.113



aarch64: incorrect emulation of sqshrn instruction
Description of problem:
`sqshrn` instruction test fails with qemu-aarch64, but passes on real aarch64 hardware.
Steps to reproduce:
1. Build [inline_asm_tests](https://cs.android.com/android/platform/superproject/main/+/main:frameworks/libs/binary_translation/tests/inline_asm_tests/) and run with qemu-aarch64
2. Observe two failures

```
[ RUN      ] Arm64InsnTest.SignedSaturatingShiftRightNarrowInt16x1
frameworks/libs/binary_translation/tests/inline_asm_tests/main_arm64.cc:6697: Failure
Expected equality of these values:
  res1
    Which is: 4294967188
  MakeUInt128(0x94U, 0U)
    Which is: 148
[  FAILED  ] Arm64InsnTest.SignedSaturatingShiftRightNarrowInt16x1 (5 ms)
[ RUN      ] Arm64InsnTest.SignedSaturatingRoundingShiftRightNarrowInt16x1
frameworks/libs/binary_translation/tests/inline_asm_tests/main_arm64.cc:6793: Failure
Expected equality of these values:
  res3
    Which is: 4294967168
  MakeUInt128(0x0000000000000080ULL, 0x0000000000000000ULL)
    Which is: 128
[  FAILED  ] Arm64InsnTest.SignedSaturatingRoundingShiftRightNarrowInt16x1 (2 ms)
```
Additional information:
[Direct link to SignedSaturatingShiftRightNarrowInt16x1 test source](https://cs.android.com/android/platform/superproject/main/+/main:frameworks/libs/binary_translation/tests/inline_asm_tests/main_arm64.cc;l=6692;drc=4ee2c3035fa5dc0b7a48b6c6dc498296be071861)