[committed][gdb/testsuite] Make gdb.dwarf2/dw2-line-number-zero.exp more robust

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

Hi,

On aarch64, there are FAILs for gdb.dwarf2/dw2-line-number-zero.exp due to
problems in the prologue analyzer (filed as PR26310).

Make the test-case more robust by avoiding to use the prologue analyzer:
...
-gdb_breakpoint "bar1"
+gdb_breakpoint "$srcfile:27"
...

Tested on x86_64-linux.

Committed to trunk.

Thanks,
- Tom

[gdb/testsuite] Make gdb.dwarf2/dw2-line-number-zero.exp more robust

gdb/testsuite/ChangeLog:

2020-07-29  Tom de Vries  <tdevries@suse.de>

	* gdb.dwarf2/dw2-line-number-zero.exp: Set breakpoints on lines
	rather than function name.

---
 gdb/testsuite/gdb.dwarf2/dw2-line-number-zero.exp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/gdb/testsuite/gdb.dwarf2/dw2-line-number-zero.exp b/gdb/testsuite/gdb.dwarf2/dw2-line-number-zero.exp
index a39256c171..12011b5f9c 100644
--- a/gdb/testsuite/gdb.dwarf2/dw2-line-number-zero.exp
+++ b/gdb/testsuite/gdb.dwarf2/dw2-line-number-zero.exp
@@ -115,13 +115,13 @@ if ![runto_main] {
     return -1
 }
 
-gdb_breakpoint "bar1"
+gdb_breakpoint "$srcfile:27"
 gdb_continue_to_breakpoint "bar1" "\[^\r\n\]*:27\r\n.*"
 
 gdb_test "n" "foo \\(2\\);" "bar1, 1st next"
 gdb_test "n" "foo \\(4\\);" "bar1, 2nd next"
 
-gdb_breakpoint "bar2"
+gdb_breakpoint "$srcfile:41"
 gdb_continue_to_breakpoint "bar2" "\[^\r\n\]*:41\r\n.*"
 
 gdb_test "n" "foo \\(2\\);" "bar2, 1st next"