[FlyDSL]add FlyDSL MoE sorting kernel

[amd-weisun]

Motivation

Add FlyDSL MoE sorting kernel.
The kernel implementation is from FlyDSL PR ROCm/FlyDSL#540

This PR includes the integration codes.
FlyDSL MoE can be enabled by AITER_USE_FLYDSL_MOE_SORTING=1 , following the style of CK kernel : AITER_USE_CK_MOE_SORTING=1. The default kernel now is OPUS.

E2E Benchmark Result

DeepSeek-R1-0528 FP8 TP8

DeepSeek-R1-0528 FP8, TP8, FP8 KV Cache, 8×MI350X
ISL=8192, OSL=1024, CONC=4, 40 prompts, 3 runs each

                  Baseline (OPUS)                          FlyDSL
Metric            Run1     Run2     Run3    Avg      Run1     Run2     Run3    Avg      Delta
─────────────────────────────────────────────────────────────────────────────────────────────
Output tok/s     329.09   329.37   328.99  329.15   336.36   336.75   337.00  336.70   +2.3%
Total tok/s     2958.34  2960.80  2957.46 2958.87  3023.69  3027.20  3029.42 3026.77   +2.3%
Mean TPOT (ms)    11.56    11.55    11.56   11.56    11.31    11.29    11.29   11.30   -2.2%
Median TPOT (ms)  11.62    11.60    11.62   11.61    11.36    11.34    11.33   11.34   -2.3%
P99 TPOT (ms)     12.00    11.99    12.00   12.00    11.76    11.74    11.72   11.74   -2.2%
Mean TTFT (ms)   277.28   279.32   278.18  278.26   276.19   277.24   275.73  276.39   -0.7%
Median TTFT (ms) 250.76   250.52   250.66  250.65   249.14   249.54   248.88  249.19   -0.6%
P99 TTFT (ms)    677.23   687.90   683.20  682.78   684.32   686.03   681.03  683.79   +0.1%
Mean ITL (ms)     11.55    11.54    11.55   11.55    11.30    11.28    11.27   11.28   -2.3%
Mean E2EL (ms) 10903.89 10897.20 10908.16 10903.08 10670.28 10655.88 10649.77 10658.64  -2.2%
P99 E2EL (ms)  12329.03 12330.07 12352.11 12337.07 12095.14 12091.76 12051.80 12079.57  -2.1%

Accuracy

                    Baseline (OPUS)          FlyDSL
flexible-extract    0.9560               0.9575 

DeepSeek-R1-0528 MXFP4 TP8

DeepSeek-R1-0528 MXFP4, TP8, FP8 KV Cache, 8×MI350X
ISL=8192, OSL=1024, CONC=4, 40 prompts, 3 runs each

                  Baseline (OPUS)                          FlyDSL
Metric            Run1     Run2     Run3    Avg      Run1     Run2     Run3    Avg      Delta
─────────────────────────────────────────────────────────────────────────────────────────────
Output tok/s     414.56   414.57   415.15  414.76   427.66   429.40   427.68  428.25   +3.3%
Total tok/s     3726.68  3726.76  3731.94 3728.46  3844.41  3860.04  3844.54 3849.66   +3.3%
Mean TPOT (ms)     9.17     9.17     9.16    9.17     8.88     8.84     8.89    8.87   -3.3%
Median TPOT (ms)   9.21     9.21     9.20    9.21     8.93     8.88     8.93    8.91   -3.3%
P99 TPOT (ms)      9.55     9.52     9.53    9.53     9.26     9.21     9.27    9.25   -2.9%
Mean TTFT (ms)   233.05   233.73   232.32  233.03   232.56   232.93   233.56  233.02   -0.0%
Median TTFT (ms) 209.85   210.47   208.41  209.58   209.78   211.99   210.06  210.61   +0.5%
P99 TTFT (ms)    583.87   583.11   583.02  583.33   585.43   586.92   584.77  585.71   +0.4%
Mean ITL (ms)      9.16     9.16     9.15    9.16     8.87     8.83     8.88    8.86   -3.3%
Mean E2EL (ms)  8663.62  8662.04  8650.62 8658.76  8397.61  8362.14  8400.81 8386.85   -3.1%
P99 E2EL (ms)   9858.62  9853.45  9832.53 9848.20  9559.02  9511.07  9558.54 9542.88   -3.1%

Accuracy

                    Baseline (OPUS)          FlyDSL
flexible-extract    0.9484            0.9492

[github-actions]

🏷️ CI Guide

Runs automatically on every PR:

• ✅ Pre-checks (submodule verification, code formatting)
• ✅ Aiter op tests (gfx942 + gfx950)
• ✅ Triton tests on MI35X (only when aiter/ops/triton/** or related paths are changed)

Extended tests (opt-in via labels):

Label	Tests
ci:triton-300x	Run an additional Triton test job on MI300X in PRs; main branch always runs both MI35X and MI300X
ci:sglang	SGLang integration tests: DeepSeek-R1-MXFP4 accuracy, Qwen 3.5 accuracy
ci:atom	ATOM benchmark: DeepSeek-R1-0528, GPT-OSS-120B
ci:atom_full	ATOM accuracy suite for PR and main models from ATOM models_accuracy.json
ci:vllm	vLLM benchmark: GPT-OSS-120B, DeepSeek-R1-0528, Kimi-K2.5
ci:all	All standard extended tests (excludes ci:atom_full)

Only add ci:atom_full for FlyDSL or Triton upgrades.
Add labels via the sidebar or gh pr edit 3266 --add-label <label>

[coderfeli]

we can use python if directly here?

[coderfeli]

use Fx.int64() directly

[coderfeli]

Too many duplicated codes.