Added -g3 flag for detailed debug information

Change-Id: Ibc5282300c549f90f6f67e99312d96601c72f52d
Reviewed-on: https://weave-review.googlesource.com/1363
Reviewed-by: Johan Euphrosine <proppy@google.com>

libweave/libweave_common.gypi

diff --git a/libweave/libweave_common.gypi b/libweave/libweave_common.gypi
index 125047d..bf81f76 100644
--- a/libweave/libweave_common.gypi
+++ b/libweave/libweave_common.gypi
@@ -18,6 +18,7 @@
         ],
         'cflags': [
           '-Og',
+          '-g3',
         ],
       },
     },