configure.ac: use -gdwarf-2 / -gstrict-dwarf when available

[Austin English]

Until we support newer versions.

-- 
-Austin
-------------- next part --------------
diff --git a/configure.ac b/configure.ac
index 4bd43d1..c80fd8a 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1746,6 +1746,8 @@ then
   WINE_TRY_CFLAGS([-Wtype-limits])
   WINE_TRY_CFLAGS([-Wunused-but-set-parameter])
   WINE_TRY_CFLAGS([-Wwrite-strings])
+  WINE_TRY_CFLAGS([-gdwarf-2])
+  WINE_TRY_CFLAGS([-gstrict-dwarf])
 
   dnl gcc-4.6+ omits frame pointers by default, breaking some copy protections
   case $host_cpu in