[gdb/testsuite] Fix exec_is_pie with gold linker

When running test-case gdb.base/break-interp.exp with target board gold, we
run into:
...
gdb compile failed, pie failed to generate PIE executable
...

The problem is that the proc exec_is_pie uses the PIE flag in the readelf -d
output, which doesn't seem to be set by the gold linker.

Instead, use the "Type" field in the readelf -h output.

Tested on x86_64-linux.

gdb/testsuite/ChangeLog:

2020-05-25  Tom de Vries  <tdevries@suse.de>

	PR testsuite/26031
	* lib/gdb.exp (exec_is_pie): Test readelf -h output.

2 files changed, 8 insertions, 2 deletions

diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index 93d5e70..d372b50 100644
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,5 +1,10 @@
 2020-05-25  Tom de Vries  <tdevries@suse.de>
 
+	PR testsuite/26031
+	* lib/gdb.exp (exec_is_pie): Test readelf -h output.
+
+2020-05-25  Tom de Vries  <tdevries@suse.de>
+
 	* boards/gold.exp: New file.
 
 2020-05-23  Tom Tromey  <tom@tromey.com>
diff --git a/gdb/testsuite/lib/gdb.exp b/gdb/testsuite/lib/gdb.exp
index f7d20bd..7177be9 100644
--- a/gdb/testsuite/lib/gdb.exp
+++ b/gdb/testsuite/lib/gdb.exp
@@ -5509,11 +5509,12 @@ proc exec_is_pie { executable } {
 	return -1
     }
     set readelf_program [gdb_find_readelf]
-    set res [catch {exec $readelf_program -d $executable} output]
+    set res [catch {exec $readelf_program -h $executable} output]
     if { $res != 0 } {
 	return -1
     }
-    set res [regexp -line {\(FLAGS_1\).*Flags:.* PIE($| )} $output]
+    set res [regexp -line {^[ \t]*Type:[ \t]*DYN \(Shared object file\)$} \
+		 $output]
     if { $res == 1 } {
 	return 1
     }