Always use TYPE_MODE instead of DECL_MODE for vector field

Always use TYPE_MODE instead of DECL_MODE for vector field

e034c5c8957 re PR target/78643 (ICE in convert_move, at expr.c:230)

fixed the case where DECL_MODE of a vector field is BLKmode and its
TYPE_MODE is a vector mode because of target attribute.  Remove the
BLKmode check for the case where DECL_MODE of a vector field is a vector
mode and its TYPE_MODE isn't a vector mode because of target attribute.

gcc/

	PR target/107304
	* expr.cc (get_inner_reference): Always use TYPE_MODE for vector
	field with vector raw mode.

gcc/testsuite/

	PR target/107304
	* gcc.target/i386/pr107304.c: New test.

(cherry picked from commit 1c64aba8cdf6509533f554ad86640f274cdbe37f)