Disable struct value printing in debug info tests

This is due to the way different versions of gdb print out structs: older versions have them always spread out with fields on different lines, while newer versions will compactly print them on one line. This makes it hard for the output checker to verify the expected output.

src/test/debug-info/struct.rs

@@ -9,17 +9,12 @@
 // except according to those terms.
 
 // compile-flags:-Z extra-debug-info
-// debugger:break 31
+// debugger:break 26
 // debugger:run
-// debugger:print pair
-// check:$1 = {
-// check:x = 1,
-// check:y = 2
-// check:}
 // debugger:print pair.x
-// check:$2 = 1
+// check:$1 = 1
 // debugger:print pair.y
-// check:$3 = 2
+// check:$2 = 2
 
 struct Pair {
     x: int,

src/test/debug-info/tuple.rs

@@ -8,6 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+// xfail-test
 // compile-flags:-Z extra-debug-info
 // debugger:break 23
 // debugger:run