Use cvt_op to save intermediate type operand instead of "subtle" vec_dest.

When there're multiple operands in vec_oprnds0, vec_dest will be
overwrited to vectype_out, but in multi_step_cvt case, cvt_type is
expected. It caused an ICE when verify_gimple_in_cfg.

gcc/ChangeLog:

	PR tree-optimization/110371
	PR tree-optimization/110018
	* tree-vect-stmts.cc (vectorizable_conversion): Use cvt_op to
	save intermediate type operand instead of "subtle" vec_dest
	for case NONE.

gcc/testsuite/ChangeLog:

	* gcc.target/aarch64/pr110371.c: New test.

1 files changed, 20 insertions, 0 deletions

diff --git a/gcc/testsuite/gcc.target/aarch64/pr110371.c b/gcc/testsuite/gcc.target/aarch64/pr110371.c
new file mode 100644
index 0000000..444e514e
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/pr110371.c
@@ -0,0 +1,20 @@
+/* { dg-do compile } */
+/* { dg-options "-O3" } */
+
+typedef struct dest
+{
+  double m[3][3];
+} dest;
+
+typedef struct src
+{
+  int m[3][3];
+} src;
+
+void
+foo (dest *a, src* s)
+{
+  for (int i = 0; i != 3; i++)
+    for (int j = 0; j != 3; j++)
+      a->m[i][j] = s->m[i][j];
+}