[gdb/testsuite] Add gcc/94469 xfails to gdb.ada/call_pn.exp

When running test-case gdb.ada/call_pn.exp with target board
unix/-flto/-O0/-flto-partition=none/-ffat-lto-objects, we run into:
...
(gdb) print last_node_id^M
Multiple matches for last_node_id^M
[0] cancel^M
[1] pck.last_node_id at gdb/testsuite/gdb.ada/call_pn/pck.adb:17^M
[2] pck.last_node_id at gdb/testsuite/gdb.ada/call_pn/foo.adb:17^M
> FAIL: gdb.ada/call_pn.exp: print last_node_id after calling pn (timeout)
...

This failure is due to a gcc bug that declares two instead of one symbols,
filed as PR gcc/94469.

Add an xfail at this test.  Also add a similar xfail at an earlier test, that
only triggers with -readnow.  Stabilize test results by making sure the
earlier xfail is always triggered, using "maint expand-symtabs".

Tested on x86_64-linux.

gdb/testsuite/ChangeLog:

2020-04-08  Tom de Vries  <tdevries@suse.de>

	PR testsuite/25760
	* gdb.ada/call_pn.exp: Call "maint expand-symtabs".  Add xfails.

2 files changed, 52 insertions, 3 deletions

diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index 8c2ace4..066a41e 100644
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2020-04-08  Tom de Vries  <tdevries@suse.de>
+
+	PR testsuite/25760
+	* gdb.ada/call_pn.exp: Call "maint expand-symtabs".  Add xfails.
+
 2020-04-07  Tom de Vries  <tdevries@suse.de>
 
 	PR symtab/25796
diff --git a/gdb/testsuite/gdb.ada/call_pn.exp b/gdb/testsuite/gdb.ada/call_pn.exp
index b21de4d..1fe133f 100644
--- a/gdb/testsuite/gdb.ada/call_pn.exp
+++ b/gdb/testsuite/gdb.ada/call_pn.exp
@@ -29,8 +29,41 @@ if ![runto "foo.adb:$bp_location" ] then {
   return
 }
 
+# The xfail mentioned below triggers for the "after" print, but may not
+# trigger for the "before" print, though it will for -readnow.  This is
+# related to PR25764 - "LOC_UNRESOLVED symbol missing from partial symtab".
+# Stabilize test results by ensuring that the xfail triggers for the "before"
+# print.
+gdb_test_no_output "maint expand-symtabs"
+
+# The xfail is for PR gcc/94469, which occurs with target board
+# unix/-flto/-O0/-flto-partition=none/-ffat-lto-objects and gcc-8 and later.
+# Note: We don't check for the filename in xfail_re because it might be
+# wrong, filed as gdb PR25771.
+set xfail_re \
+    [multi_line \
+	 "Multiple matches for last_node_id" \
+	 "\\\[0\\\] cancel" \
+	 "\\\[1\\\] pck\.last_node_id at .*.adb:17" \
+	 "\\\[2\\\] pck\.last_node_id at .*.adb:17" \
+	 "> $"]
+
 # Make sure that last_node_id is set to zero...
-gdb_test "print last_node_id" "= 0" "print last_node_id before calling pn"
+gdb_test_multiple "print last_node_id" "print last_node_id before calling pn" {
+    -re $xfail_re {
+	xfail $gdb_test_name
+	# One of the choices will print the correct value, the other one
+	# <optimized out>.  Since we don't known which one to choose to get
+	# the correct value, cancel.
+	gdb_test_multiple "0" "cancel after xfail 1" {
+	    -re -wrap "cancelled" {
+	    }
+	}
+    }
+    -re -wrap "= 0" {
+	pass $gdb_test_name
+    }
+}
 
 # Now, call procedure Pn, which should set Last_Node_Id to the value
 # of the parameter used in the function call.  Verify that we can print
@@ -38,5 +71,16 @@ gdb_test "print last_node_id" "= 0" "print last_node_id before calling pn"
 gdb_test "print pn (4321)" "= 4321"
 
 # Make sure that last_node_id now has the correct value...
-gdb_test "print last_node_id" "= 4321" "print last_node_id after calling pn"
-
+gdb_test_multiple "print last_node_id" "print last_node_id after calling pn" {
+    -re $xfail_re {
+	xfail $gdb_test_name
+	# Cancel
+	gdb_test_multiple "0" "cancel after xfail 2" {
+	    -re -wrap "cancelled" {
+	    }
+	}
+    }
+    -re -wrap "= 4321" {
+	pass $gdb_test_name
+    }
+}