Don't use vec_disp8 encoding with the .d32 suffix

Don't use vec_disp8 encoding with the .d32 suffix

Since the .d32 suffix prefers 32-bit displacement in encoding, try
vec_disp8 encoding only if i.disp_encoding != disp_encoding_32bit.

	PR gas/19909
	* config/tc-i386.c (check_VecOperands): Try vec_disp8 encoding
	only if i.disp_encoding != disp_encoding_32bit.
	* gas/testsuite/gas/i386/disp32.s: Add tests for vmovdqu64.d32.
	* gas/testsuite/gas/i386/x86-64-disp32.s: Likewise.
	* gas/testsuite/gas/i386/disp32.d: Updated.
	* gas/testsuite/gas/i386/x86-64-disp32.d: Likewise.