-gdwarf-2 harder the test.

llvm-svn: 211236
diff --git a/clang-tests-external/gdb/7.5/gdb/testsuite/gdb.base/prelink.exp b/clang-tests-external/gdb/7.5/gdb/testsuite/gdb.base/prelink.exp
index 08aa29c..9179224 100644
--- a/clang-tests-external/gdb/7.5/gdb/testsuite/gdb.base/prelink.exp
+++ b/clang-tests-external/gdb/7.5/gdb/testsuite/gdb.base/prelink.exp
@@ -40,7 +40,7 @@
 
 # Use -soname so that the new library gets copied by build_executable_own_libs.
 
-if { [gdb_compile_shlib "${srcdir}/${subdir}/${libsrcfile}" "${libfile}" [list debug "ldflags=-Wl,-soname,[file tail ${libfile}]"]] != ""} {
+if { [gdb_compile_shlib "${srcdir}/${subdir}/${libsrcfile}" "${libfile}" [list debug "additional_flags=-gdwarf-2" "ldflags=-Wl,-soname,[file tail ${libfile}]"]] != ""} {
     # If creating the shared library fails, maybe we don't have the right tools
     return -1
 }