[gdb/testsuite] Debug gdb.arch/i386-sse.exp

There's a failure filed at PR28504 - "FAIL: gdb.arch/i386-sse.exp: check
contents of data[2]" that sofar hasn't been reproduced outside OBS.

This patch adds printing of more info to help make sense of it.

---
 gdb/testsuite/gdb.arch/i386-sse.exp | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/gdb/testsuite/gdb.arch/i386-sse.exp b/gdb/testsuite/gdb.arch/i386-sse.exp
index fca90256505..4b434abe904 100644
--- a/gdb/testsuite/gdb.arch/i386-sse.exp
+++ b/gdb/testsuite/gdb.arch/i386-sse.exp
@@ -75,6 +75,9 @@ if [is_amd64_regs_target] {
     set nr_regs 8
 }
 
+gdb_test_no_output "set debug arch 1"
+gdb_test_no_output "set debug target 1"
+
 for { set r 0 } { $r < $nr_regs } { incr r } {
     gdb_test "print \$xmm$r.v4_float" \
         ".. = \\{$r, $r.25, $r.5, $r.75\\}.*" \
@@ -86,6 +89,9 @@ for { set r 0 } { $r < $nr_regs } { incr r } {
 
 for { set r 0 } { $r < $nr_regs } { incr r } {
     gdb_test "set var \$xmm$r.v4_float\[0\] = $r + 10" "" "set %xmm$r"
+    gdb_test "print \$xmm$r.v4_float" \
+        ".. = \\{[expr $r + 10], $r.25, $r.5, $r.75\\}.*" \
+        "check float contents of %xmm$r after add"
 }
 
 gdb_test "break [gdb_get_line_number "second breakpoint here"]" \
@@ -93,6 +99,11 @@ gdb_test "break [gdb_get_line_number "second breakpoint here"]" \
          "set second breakpoint in main"
 gdb_continue_to_breakpoint "continue to second breakpoint in main"
 
+for { set r 0 } { $r < $nr_regs } { incr r } {
+    gdb_test "print \$xmm$r.v4_float" \
+        ".. = \\{[expr $r + 10], $r.25, $r.5, $r.75\\}.*" \
+        "check float contents of %xmm$r at second breakpoint"
+}
 for { set r 0 } { $r < $nr_regs } { incr r } {
     gdb_test "print data\[$r\]" \
         ".. = \\{f = \\{[expr $r + 10], $r.25, $r.5, $r.75\\}\\}.*" \