runtime: disable compressed DWARF for lldb test

lldb doesn't support compressed DWARF, so right now we're just always
skipping the lldb test. This CL makes the test run again by disabling
compressed DWARF just for this test.

Updates #25925.

Change-Id: Ib9ddc442305fe6d37060d48f36bc4458b6fd8c86
Reviewed-on: https://go-review.googlesource.com/124385
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

src/runtime/runtime-lldb_test.go

@@ -159,7 +159,9 @@ func TestLldbPython(t *testing.T) {
 		t.Fatalf("failed to create file: %v", err)
 	}
 
-	cmd := exec.Command(testenv.GoToolPath(t), "build", "-gcflags=all=-N -l", "-o", "a.exe")
+	// As of 2018-07-17, lldb doesn't support compressed DWARF, so
+	// disable it for this test.
+	cmd := exec.Command(testenv.GoToolPath(t), "build", "-gcflags=all=-N -l", "-ldflags=-compressdwarf=false", "-o", "a.exe")
 	cmd.Dir = dir
 	out, err := cmd.CombinedOutput()
 	if err != nil {