Fix libinproctrace.so build on PPC

The recent gnulib import caused a build failure of libinproctrace.so
on PPC:

    alloc.c:(.text+0x20): undefined reference to `rpl_malloc'
    alloc.c:(.text+0x70): undefined reference to `rpl_realloc'

This patch fixes the problem using the same workaround that was
previously used for free.

gdbserver/Makefile.in

@@ -470,7 +470,8 @@ UST_CFLAGS = $(ustinc) -DCONFIG_UST_GDB_INTEGRATION
 # Undo gnulib replacements for the IPA shared library build.
 # The gnulib headers are still needed, but gnulib is not linked
 # into the IPA lib so replacement apis don't work.
-UNDO_GNULIB_CFLAGS = -Drpl_strerror_r=strerror_r -Drpl_free=free
+UNDO_GNULIB_CFLAGS = -Drpl_strerror_r=strerror_r -Drpl_free=free \
+	-Drpl_malloc=malloc -Drpl_realloc=realloc
 
 # Note, we only build the IPA if -fvisibility=hidden is supported in
 # the first place.