Use -g instead of -gstabs in AFLAGS_DEBUG

Patch by Haavard Skinnemoen, 30 Aug 2006

In config.mk, -Wa,-gstabs is unconditionally appended to AFLAGS no
matter what the target's preferred debugging format is. This patch
simply replaces -gstabs with -g, so that the default debugging format
for the architecture is used.

config.mk

@@ -169,7 +169,7 @@ CFLAGS := $(CPPFLAGS) -Wall -Wno-trigraphs
 endif
 endif
 
-AFLAGS_DEBUG := -Wa,-gstabs
+AFLAGS_DEBUG := -Wa,-g
 
 # turn jbsr into jsr for m68k
 ifeq ($(ARCH),m68k)