On x86, when AVX and AVX512 are enabled, vector move instructions can
be encoded with either 2-byte/3-byte VEX (AVX) or 4-byte EVEX (AVX512):

   0:	c5 f9 6f d1          	vmovdqa %xmm1,%xmm2
   4:	62 f1 fd 08 6f d1    	vmovdqa64 %xmm1,%xmm2

We prefer VEX encoding over EVEX since VEX is shorter.  Also AVX512F
only supports 512-bit vector moves.  AVX512F + AVX512VL supports 128-bit
and 256-bit vector moves.  xmm16-xmm31 and ymm16-ymm31 are disallowed in
128-bit and 256-bit modes when AVX512VL is disabled.  Mode attributes on
x86 vector move patterns indicate target preferences of vector move
encoding.  For scalar register to register move, we can use 512-bit
vector move instructions to move 32-bit/64-bit scalar if AVX512VL isn't
available.  With AVX512F and AVX512VL, we should use VEX encoding for
128-bit/256-bit vector moves if upper 16 vector registers aren't used.
This patch adds a function, ix86_output_ssemov, to generate vector moves:

1. If zmm registers are used, use EVEX encoding.
2. If xmm16-xmm31/ymm16-ymm31 registers aren't used, SSE or VEX encoding
will be generated.
3. If xmm16-xmm31/ymm16-ymm31 registers are used:
   a. With AVX512VL, AVX512VL vector moves will be generated.
   b. Without AVX512VL, xmm16-xmm31/ymm16-ymm31 register to register
      move will be done with zmm register move.

There is no need to set mode attribute to XImode explicitly since
ix86_output_ssemov can properly encode xmm16-xmm31/ymm16-ymm31 registers
with and without AVX512VL.

Tested on AVX2 and AVX512 with and without --with-arch=native.

gcc/

	PR target/89229
	PR target/89346
	* config/i386/i386-protos.h (ix86_output_ssemov): New prototype.
	* config/i386/i386.c (ix86_get_ssemov): New function.
	(ix86_output_ssemov): Likewise.
	* config/i386/sse.md (VMOVE:mov<mode>_internal): Call
	ix86_output_ssemov for TYPE_SSEMOV.  Remove TARGET_AVX512VL
	check.
	(*movxi_internal_avx512f): Call ix86_output_ssemov for TYPE_SSEMOV.
	(*movoi_internal_avx): Call ix86_output_ssemov for TYPE_SSEMOV.
	Remove ext_sse_reg_operand and TARGET_AVX512VL check.
	(*movti_internal): Likewise.
	(*movtf_internal): Call ix86_output_ssemov for TYPE_SSEMOV.

gcc/testsuite/

	PR target/89229
	PR target/89346
	* gcc.target/i386/avx512vl-vmovdqa64-1.c: Updated.
	* gcc.target/i386/pr89229-2a.c: New test.
	* gcc.target/i386/pr89229-2b.c: Likewise.
	* gcc.target/i386/pr89229-2c.c: Likewise.
	* gcc.target/i386/pr89229-3a.c: Likewise.
	* gcc.target/i386/pr89229-3b.c: Likewise.
	* gcc.target/i386/pr89229-3c.c: Likewise.
	* gcc.target/i386/pr89346.c: Likewise.