i386: Fix expand_vector_set for VEC_MERGE/VEC_DUPLICATE RTX [PR117116]

Middle end can generate SYMBOL_REF RTX as a value "val" in the call
to expand_vector_set, but SYMBOL_REF RTX is not accepted in
<sse2p4_1>_pinsr<ssemodesuffix> insn pattern, generated via
VEC_MERGE/VEC_DUPLICATE RTX path.

Force the value into a register before VEC_MERGE/VEC_DUPLICATE RTX
is generated if it doesn't satisfy nonimmediate_operand predicate.

	PR target/117116

gcc/ChangeLog:

	* config/i386/i386-expand.cc (expand_vector_set): Force "val"
	into a register before VEC_MERGE/VEC_DUPLICATE RTX is generated
	if it doesn't satisfy nonimmediate_operand predicate.

gcc/testsuite/ChangeLog:

	* gcc.target/i386/pr117116.c: New test.

(cherry picked from commit 80d7032)

gcc/config/i386/i386-expand.cc

@@ -16541,6 +16541,8 @@ ix86_expand_vector_set (bool mmx_ok, rtx target, rtx val, int elt)
   else if (use_vec_merge)
     {
 do_vec_merge:
+      if (!nonimmediate_operand (val, inner_mode))
+	val = force_reg (inner_mode, val);
       tmp = gen_rtx_VEC_DUPLICATE (mode, val);
       tmp = gen_rtx_VEC_MERGE (mode, tmp, target,
 			       GEN_INT (HOST_WIDE_INT_1U << elt));

gcc/testsuite/gcc.target/i386/pr117116.c

@@ -0,0 +1,18 @@
+/* PR target/117116 */
+/* { dg-do compile } */
+/* { dg-options "-O2 -mavx2" } */
+
+typedef void (*StmFct)();
+typedef struct {
+  StmFct fct_getc;
+  StmFct fct_putc;
+  StmFct fct_flush;
+  StmFct fct_close;
+} StmInf;
+
+StmInf TTY_Getc_pstm;
+
+void TTY_Getc() {
+  TTY_Getc_pstm.fct_getc = TTY_Getc;
+  TTY_Getc_pstm.fct_putc = TTY_Getc_pstm.fct_flush = TTY_Getc_pstm.fct_close = (StmFct)1;
+}