Make the assembler generate whatever debuginfo it can
--- openjdk/hotspot/make/linux/makefiles/rules.make
+++ openjdk/hotspot/make/linux/makefiles/rules.make
@@ -34,7 +34,7 @@
 CC_COMPILE       = $(CC) $(CXXFLAGS) $(CFLAGS)
 CXX_COMPILE      = $(CXX) $(CXXFLAGS) $(CFLAGS)
 
-AS.S            = $(AS) $(ASFLAGS)
+AS.S            = $(AS) -g $(ASFLAGS)
 
 COMPILE.CC       = $(CC_COMPILE) -c
 GENASM.CC        = $(CC_COMPILE) -S
@@ -161,12 +161,12 @@
 %.o: %.s
 	@echo Assembling $<
 	$(QUIETLY) $(REMOVE_TARGET)
-	$(QUIETLY) $(AS.S) $(DEPFLAGS) -o $@ $< $(COMPILE_DONE)
+	$(QUIETLY) $(AS.S) -g $(DEPFLAGS) -o $@ $< $(COMPILE_DONE)
 
 %.o: %.S
 	@echo Assembling $<
 	$(QUIETLY) $(REMOVE_TARGET)
-	$(COMPILE.CC) -o $@ $< $(COMPILE_DONE)
+	$(COMPILE.CC) -g -o $@ $< $(COMPILE_DONE)
 
 %.s: %.cpp
 	@echo Generating assembly for $<