Backport from gcc git
https://gcc.gnu.org/git/?p=gcc.git;a=commitdiff;h=f151e2adc9c93b5d65f551f087077609821b71b7

diff -Nur gcc-5.3.0.orig/gcc/config.gcc gcc-5.3.0/gcc/config.gcc
--- gcc-5.3.0.orig/gcc/config.gcc	2015-09-10 16:17:53.000000000 +0200
+++ gcc-5.3.0/gcc/config.gcc	2016-04-02 19:51:24.771406949 +0200
@@ -1805,7 +1805,7 @@
         md_file=iq2000/iq2000.md
         ;;
 lm32-*-elf*)
-        tm_file="dbxelf.h elfos.h ${tm_file}"
+        tm_file="dbxelf.h elfos.h ${tm_file} newlib-stdint.h"
 	tmake_file="${tmake_file} lm32/t-lm32"
         ;;
 lm32-*-rtems*)