Don't load libtcc1 on arch where it doesn't exist

ARM architecture doesn't have any libtcc1 implementation but tcc load
libtcc1.a in all case. This patch add a conditional preprocessor
instruction to load libtcc1.a only when there is an implementation for
the target architecture.

Makefile

@@ -49,6 +49,7 @@ endif
 
 ifeq ($(ARCH),arm)
 NATIVE_DEFINES=-DTCC_TARGET_ARM
+NATIVE_TARGET=-DWITHOUT_LIBTCC
 NATIVE_DEFINES+=$(if $(wildcard /lib/ld-linux.so.3),-DTCC_ARM_EABI)
 NATIVE_DEFINES+=$(if $(shell grep -l "^Features.* \(vfp\|iwmmxt\) " /proc/cpuinfo),-DTCC_ARM_VFP)
 endif