[gdb/testsuite] Handle PAC marker

On aarch64-linux, I run into:
...
FAIL: gdb.base/annota1.exp: backtrace from shlibrary (timeout)
...
due to the PAC marker showing up:
...
^Z^Zframe-address^M
0x000000000041025c [PAC]^M
^Z^Zframe-address-end^M
...

In the docs the marker is documented as follows:
...
When GDB is debugging the AArch64 architecture, and the program is using the
v8.3-A feature Pointer Authentication (PAC), then whenever the link register
$lr is pointing to an PAC function its value will be masked.  When GDB prints
a backtrace, any addresses that required unmasking will be postfixed with the
marker [PAC].  When using the MI, this is printed as part of the addr_flags
field.
...

Update the test-case to allow the PAC marker.

Likewise in a few other test-cases.

While we're at it, rewrite the affected pattern pat_begin in annota1.exp into
a more readable form.  Likewise for the corresponding pat_end.

Tested on aarch64-linux.

Approved-By: Luis Machado <luis.machado@arm.com>

PR testsuite/31202
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=31202

2 files changed, 2 insertions, 2 deletions

diff --git a/gdb/testsuite/gdb.threads/pthread_cond_wait.exp b/gdb/testsuite/gdb.threads/pthread_cond_wait.exp
index ff3097c..b29be9e 100644
--- a/gdb/testsuite/gdb.threads/pthread_cond_wait.exp
+++ b/gdb/testsuite/gdb.threads/pthread_cond_wait.exp
@@ -51,7 +51,7 @@ global decimal
 #
 # This is a "backtrace break" ("btb"):
 #
-set btb "\[^\r\n\]+\[\r\n\]+\#${decimal}\[ \t\]+${hex} in "
+set btb "\[^\r\n\]+\[\r\n\]+\#${decimal}\[ \t\]+${hex} (\\\[PAC\\\] )?in "
 
 # One of the threads is blocked on a call to pthread_cond_wait, and
 # we want to verify that we are able to get a sensible backtrace for
diff --git a/gdb/testsuite/gdb.threads/tls.exp b/gdb/testsuite/gdb.threads/tls.exp
index 89f6fb8..91a7f80 100644
--- a/gdb/testsuite/gdb.threads/tls.exp
+++ b/gdb/testsuite/gdb.threads/tls.exp
@@ -132,7 +132,7 @@ proc check_thread_stack {number spin_threads spin_threads_level} {
     }
     send_gdb "where\n"
     gdb_expect {
-	-re ".*(\[0-9\]+)\[ \t\]+$hex in spin \\(vp=(0x\[0-9a-f\]+).*\r\n$gdb_prompt $" {
+	-re ".*(\[0-9\]+)\[ \t\]+$hex (\\\[PAC\\\] )?in spin \\(vp=(0x\[0-9a-f\]+).*\r\n$gdb_prompt $" {
 	    if {[info exists tarr($number)]} {
 		fail "backtrace of thread number $number in spin"
 	    } else {