arm: allow to build with DODEBUG=y

Avoids following linking error:
/usr/lib/gcc/arm-openadk-linux-uclibceabihf/5.3.0/libgcc.a(unwind-arm.o):
In function `unwind_phase2':
../w-gcc-5.3.0-1/gcc-5.3.0/libgcc/unwind-arm-common.inc:289:
undefined reference to `abort'
/usr/lib/gcc/arm-openadk-linux-uclibceabihf/5.3.0/libgcc.a(unwind-arm.o):
In function `unwind_phase2_forced':
../w-gcc-5.3.0-1/gcc-5.3.0/libgcc/unwind-arm-common.inc:346:
undefined reference to `memcpy'
collect2: error: ld returned 1 exit status

ldso/ldso/Makefile.in

@@ -14,6 +14,13 @@ ifneq ($(TARGET_ARCH),arc)
 CFLAGS-rtld += -fno-omit-frame-pointer
 endif
 
+ifeq ($(DODEBUG),y)
+ifeq ($(TARGET_ARCH),arm)
+# This stuff will not work with -funwind-tables / -fasynchronous-unwind-tables
+CFLAGS-rtld += -fno-unwind-tables -fno-asynchronous-unwind-tables
+endif
+endif
+
 CFLAGS-rtld += -I$(top_srcdir)ldso/ldso/$(TARGET_ARCH) -I$(top_srcdir)ldso/include -I$(top_srcdir)ldso/ldso
 CFLAGS-rtld += -DUCLIBC_RUNTIME_PREFIX=\"$(RUNTIME_PREFIX)\" -DUCLIBC_LDSO=\"$(UCLIBC_LDSO)\"