Mention used workaround in dwz.log

Add a mechanism where tests can add text to a file dwz.info, which is
then included in the dwz.log file.

Use the mechanism to mention the workaround used in twice-multifile.sh.

2019-03-17  Tom de Vries  <tdevries@suse.de>

	* testsuite/dwz.tests/twice-multifile.sh: Mention workaround in
	dwz.info.
	* testsuite/dwz.tests/dwz-tests.exp: Include dwz.info in dwz.log.

---
 testsuite/dwz.tests/dwz-tests.exp      | 6 ++++++
 testsuite/dwz.tests/twice-multifile.sh | 3 +--
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/testsuite/dwz.tests/dwz-tests.exp b/testsuite/dwz.tests/dwz-tests.exp
index 983d323..5a0b551 100644
--- a/testsuite/dwz.tests/dwz-tests.exp
+++ b/testsuite/dwz.tests/dwz-tests.exp
@@ -42,6 +42,12 @@ foreach test $tests {
 	puts "$msg"
 	fail "$test"
     } else {
+	if { [file exists dwz.info ] } {
+	    set info [exec cat dwz.info]
+	    verbose -log "$test:" 1
+	    verbose -log "$info" 1
+	    exec rm -f dwz.info
+	}
 	set file_list [glob -nocomplain "$dir/*"]
 	if {[llength $file_list] != 0} {
 	    puts "$dir is not empty"
diff --git a/testsuite/dwz.tests/twice-multifile.sh b/testsuite/dwz.tests/twice-multifile.sh
index fded77a..a0d023a 100644
--- a/testsuite/dwz.tests/twice-multifile.sh
+++ b/testsuite/dwz.tests/twice-multifile.sh
@@ -25,8 +25,7 @@ if [ $(grep -qv "DWARF compression not beneficial" dwz.err \
 fi
 
 if [ $status -eq 1 ]; then
-    # PR24354
-    true
+    echo "PR24354 workaround used" > dwz.info
 else
     [ $status -eq 0 ]
 fi