QB4W SSE2/SSE41 GEMM Kernels

[mcr229]

This pull requests adds blockwise 4-bit (qb4w) GEMM microkernels targetinsg x86 SSE2 and SSE4.1 Instruction Family.

Note: This PR includes one commit from https://github.com/google/XNNPACK/pull/6557 (Test generation update for qb4w). I'm putting this PR up for review before that PR merges so that we can start the review process.

Tests and Benchmarks were run on Icelake Xeon Processor. block_size equal to KC are functionally equivalent to QC4W, so QC4W provides a reasonable performance comparison.

SSE2 Benchmarks

AVERAGE of OPS
				M	128
				N	16	128	4096	11008	32000
Tile Size	Kernel	BL	Kernel Type	K	1024	1024	1024	4096	4096
1x4c8	qd8_f32_qb4w	32	sse2_ld128		16.3626	16.5004	16.4693	16.2591	15.1152
			sse2_ld64		13.8485	13.8654	13.7583	13.7609	12.9008
		256	sse2_ld128		19.1497	19.1257	19.2257	19.0563	17.9628
			sse2_ld64		15.5274	15.5863	15.541	15.4571	14.8878
	qd8_f32_qc4w		sse2_ld128		19.0017	19.3572	19.4491	19.1485	18.5355
			sse2_ld64		15.364	15.311	15.4119	15.3349	15.4244
2x4c8	qd8_f32_qb4w	32	sse2_ld128		19.7986	19.7132	19.3471	19.874	19.457
			sse2_ld64		15.0903	16.8612	13.1044	16.8245	17.2448
		256	sse2_ld128		24.3207	24.276	24.263	24.386	23.4275
			sse2_ld64		16.5991	19.1659	17.5122	20.0571	21.1375
	qd8_f32_qc4w		sse2_ld128		24.7754	24.3957	24.3669	25.0426	24.9166
			sse2_ld64		21.6573	21.4722	21.3531	21.6695	21.7461
3x4c8	qd8_f32_qb4w	32	sse2_ld128		21.0667	20.9242	20.4278	21.1425	20.9614
			sse2_ld64		19.7949	19.862	19.8228	19.78	19.6134
		256	sse2_ld128		26.2247	25.7603	26.5098	26.3606	26.2232
			sse2_ld64		24.0754	24.1035	24.1776	24.1109	23.6717
	qd8_f32_qc4w		sse2_ld128		26.8972	27.2868	27.1239	27.4936	27.3707
			sse2_ld64		24.008	23.7783	24.4216	24.9255	24.7481
4x4c8	qd8_f32_qb4w	32	sse2_ld128		21.546	21.2863	21.9667	22.0366	21.8368
			sse2_ld64		20.2396	20.4829	20.3171	20.1945	20.327
		256	sse2_ld128		27.4331	27.4372	27.6257	27.7552	27.7811
			sse2_ld64		25.1659	25.7404	25.4879	25.5119	25.4176
	qd8_f32_qc4w		sse2_ld128		28.0353	28.4844	28.1422	28.431	28.4336
			sse2_ld64		26.1268	26.5393	26.4284	26.8376	26.746

SSE4.1 Benchmarks

AVERAGE of OPS
				M	128
				N	16	128	4096	11008	32000
Tile Size	Kernel	BL	Kernel Type	K	1024	1024	1024	4096	4096
1x4c8	qd8_f32_qb4w	32	sse41_ld128		17.3014	17.3535	17.2064	17.1379	16.0412
			sse41_ld64		16.9989	16.8812	16.9124	16.8923	16.2466
		256	sse41_ld128		20.1779	20.2345	20.2459	20.2033	19.4152
			sse41_ld64		19.4751	19.1835	19.4524	19.2826	18.5472
	qd8_f32_qc4w	N/A	sse41_ld128		20.4684	20.5874	20.1799	20.5715	18.9625
			sse41_ld64		19.6819	19.3431	19.7433	19.5436	19.2356
2x4c8	qd8_f32_qb4w	32	sse41_ld128		21.2354	21.1893	21.1614	20.9931	20.8421
			sse41_ld64		21.3569	21.4488	21.235	20.9837	21.0178
		256	sse41_ld128		26.0017	25.9916	25.4473	25.5135	25.57
			sse41_ld64		25.2493	25.7025	26.085	25.9694	25.2185
	qd8_f32_qc4w	N/A	sse41_ld128		26.8566	27.1628	27.0692	27.3674	26.9184
			sse41_ld64		26.183	26.2211	26.139	26.5423	26.6486
3x4c8	qd8_f32_qb4w	32	sse41_ld128		22.6084	22.5638	22.2168	22.7137	22.4851
			sse41_ld64		22.2074	22.2576	22.1917	22.2111	21.9517
		256	sse41_ld128		28.6587	28.6288	29.0569	28.9576	28.5065
			sse41_ld64		28.233	28.3912	28.5254	28.3961	28.1014
	qd8_f32_qc4w	N/A	sse41_ld128		29.2685	29.6141	29.612	29.7231	29.4312
			sse41_ld64		29.0769	29.047	29.7566	30.0988	29.7775
4x4c8	qd8_f32_qb4w	32	sse41_ld128		23.4833	22.5307	23.0766	23.3969	23.209
			sse41_ld64		23.0014	23.5207	23.657	23.5848	23.4027
		256	sse41_ld128		30.0163	29.9047	30.2299	30.367	29.8178
			sse41_ld64		30.0503	29.1273	29.8003	30.3124	30.0438
	qd8_f32_qc4w	N/A	sse41_ld128		30.7884	31.3583	31.1508	31.4678	30.5934
			sse41_ld64		31.2101	30.8091	31.3049	31.2445	31.8041