Turn dead-code removal back on when not simulavr

Makefile-AVR

@@ -127,13 +127,14 @@ CFLAGS += -finline-functions-called-once
 CFLAGS += -mcall-prologues
 
 LDFLAGS  = -Wl,--as-needed
-# Doesn't work for simulavr, can't allow dead code removal.
-#LDFLAGS += -Wl,--gc-sections
 
 ifneq ($(realpath ../simulavr/src/simulavr_info.h),)
   # Neccessary for simulavr support, doesn't hurt others.
   CFLAGS += -DSIMINFO
   LDFLAGS += -Wl,--section-start=.siminfo=0x900000
+else
+  # Doesn't work for simulavr, can't allow dead code removal.
+  LDFLAGS += -Wl,--gc-sections
 endif
 
 LIBS  = -lm