More changes for modern gcc compat

Makefile

@@ -108,11 +108,6 @@ sound/%.bin: sound/%.aif ; $(AIF) $< $@
 sound/songs/%.s: sound/songs/%.mid
 	cd $(@D) && ../../$(MID) $(<F)
 
-$(C_BUILDDIR)/libc.o: CC1 := tools/agbcc/bin/old_agbcc
-$(C_BUILDDIR)/libc.o: CFLAGS := -O2
-
-$(C_BUILDDIR)/siirtc.o: CFLAGS := -mthumb-interwork
-
 $(C_BUILDDIR)/agb_flash.o: CFLAGS := -O -mthumb-interwork
 $(C_BUILDDIR)/agb_flash_1m.o: CFLAGS := -O -mthumb-interwork
 $(C_BUILDDIR)/agb_flash_mx.o: CFLAGS := -O -mthumb-interwork