[PATCH][gdb/testsuite] Compile index-cache.c with -Wl,--build-id

[Tom de Vries <tdevries@suse.de>]

Hi,

When building gdb using a combined gcc/binutils-gdb build and running
gdb.base/index-cache.exp we get:
...
FAIL: gdb.base/index-cache.exp: test_cache_enabled_miss: at least one file was created
FAIL: gdb.base/index-cache.exp: test_cache_enabled_miss: couldn't get executable build id
FAIL: gdb.base/index-cache.exp: test_cache_enabled_hit: check index-cache stats
...

With "set debug index-cache on" we get:
...
(gdb) file index-cache
Reading symbols from index-cache...
index cache: objfile index-cache has no build id
...

The problem is that the vanilla toolchain does not add a build-id, which is
required for the index-cache functionality.

Fix this by compiling index-cache.c with -Wl,--build-id.

Tested on x86_64-linux.

OK for trunk?

Thanks,
- Tom

[gdb/testsuite] Compile index-cache.c with -Wl,--build-id

gdb/testsuite/ChangeLog:

2019-06-21  Tom de Vries  <tdevries@suse.de>

	* gdb.base/index-cache.exp: Add additional_flags=-Wl,--build-id.

---
 gdb/testsuite/gdb.base/index-cache.exp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/gdb/testsuite/gdb.base/index-cache.exp b/gdb/testsuite/gdb.base/index-cache.exp
index 075dffe3f5..6f1488e037 100644
--- a/gdb/testsuite/gdb.base/index-cache.exp
+++ b/gdb/testsuite/gdb.base/index-cache.exp
@@ -18,7 +18,8 @@
 
 standard_testfile
 
-if { [prepare_for_testing "failed to prepare" $testfile $srcfile] } {
+if { [prepare_for_testing "failed to prepare" $testfile $srcfile \
+	  {additional_flags=-Wl,--build-id}] } {
     return
 }