Make bench program buildable and update git submodules

Makefile

@@ -1,3 +1,8 @@
+# Git
+GIT=git
+GIT_SUBMODULES=$(shell sed -nE 's/path = +(.+)/\1\/.git/ p' .gitmodules | paste -s -)
+
+# Flags
 CFLAGS = -std=gnu99 -O2 -Wall -Wextra
 LDFLAGS = -lm
 
@@ -19,7 +24,7 @@ endif
 OUT ?= build
 SHELL_HACK := $(shell mkdir -p $(OUT))
 
-BIN = $(OUT)/emu $(OUT)/bench
+BIN = $(OUT)/emu $(GIT_SUBMODULES) $(OUT)/bench
 
 all: $(BIN)
 
@@ -50,9 +55,14 @@ $(OUT)/cpu_instrs.h: tests/cpu_instrs.gb tests/rom2h.c
 	$(Q)$(CC) -o $(OUT)/rom2h tests/rom2h.c
 	@$(OUT)/rom2h
 
-$(OUT)/bench: $(OUT)/cpu_instrs.h prof.h cpu.c bench.c gameboy.h
+$(GIT_SUBMODULES): %/.git: .gitmodules
+	$(GIT) submodule update --init $*
+	@touch $@
+
+$(OUT)/bench: gbit/lib/tester.c gbit/lib/ref_cpu.c gbit/lib/inputstate.c gbit/lib/disassembler.c
 	$(VECHO) "  CC+LD\t$@\n"
-	$(Q)$(CC) -DENABLE_LCD=0 -o $@ cpu.c bench.c
+	$(Q)$(CC) -DENABLE_LCD=0 -DDEBUG -o $@ cpu.c bench.c $^
+
 
 # Download Game Boy ROMs with full source
 download_rom: