rs6000: Fix vec insert ilp32 ICE and test failures [PR98799]

rs6000: Fix vec insert ilp32 ICE and test failures [PR98799]

UNSPEC_SI_FROM_SF is not supported when TARGET_DIRECT_MOVE_64BIT
is false for -m32, don't generate VIEW_CONVERT_EXPR(ARRAY_REF) for
variable vector insert.  Remove rs6000_expand_vector_set_var helper
function, adjust the p8 and p9 definitions position and make them
static.

The previous commit r11-6858 missed check m32, This patch is tested pass
on P7BE{m32,m64}/P8BE{m32,m64}/P8LE/P9LE with
RUNTESTFLAGS="--target_board =unix'{-m32,-m64}'" for BE targets.

gcc/ChangeLog:

2021-01-27  Xionghu Luo  <luoxhu@linux.ibm.com>
	    David Edelsohn  <dje.gcc@gmail.com>

	PR target/98799
	* config/rs6000/rs6000-c.c (altivec_resolve_overloaded_builtin):
	Don't generate VIEW_CONVERT_EXPR for fcode ALTIVEC_BUILTIN_VEC_INSERT
	when -m32.
	* config/rs6000/rs6000-protos.h (rs6000_expand_vector_set_var):
	Delete.
	* config/rs6000/rs6000.c (rs6000_expand_vector_set): Remove the
	wrapper call rs6000_expand_vector_set_var for cleanup.  Call
	rs6000_expand_vector_set_var_p9 and rs6000_expand_vector_set_var_p8
	directly.
	(rs6000_expand_vector_set_var): Delete.
	(rs6000_expand_vector_set_var_p9): Make static.
	(rs6000_expand_vector_set_var_p8): Make static.

gcc/testsuite/ChangeLog:

2021-01-27  Xionghu Luo  <luoxhu@linux.ibm.com>

	PR target/98827
	* gcc.target/powerpc/fold-vec-insert-char-p8.c: Adjust ilp32.
	* gcc.target/powerpc/fold-vec-insert-char-p9.c: Likewise.
	* gcc.target/powerpc/fold-vec-insert-double.c: Likewise.
	* gcc.target/powerpc/fold-vec-insert-float-p8.c: Likewise.
	* gcc.target/powerpc/fold-vec-insert-float-p9.c: Likewise.
	* gcc.target/powerpc/fold-vec-insert-int-p8.c: Likewise.
	* gcc.target/powerpc/fold-vec-insert-int-p9.c: Likewise.
	* gcc.target/powerpc/fold-vec-insert-longlong.c: Likewise.
	* gcc.target/powerpc/fold-vec-insert-short-p8.c: Likewise.
	* gcc.target/powerpc/fold-vec-insert-short-p9.c: Likewise.
	* gcc.target/powerpc/pr79251.p8.c: Likewise.
	* gcc.target/powerpc/pr79251.p9.c: Likewise.
	* gcc.target/powerpc/vsx-builtin-7.c: Likewise.
	* gcc.target/powerpc/pr79251-run.c: Build and run with vsx
	option.