Added patch for missing sys/ustat.h header file

Fix for cloudera#57

source/gcc/build.sh

@@ -76,7 +76,7 @@ if [ ! -f $SOURCE_DIR/check/$PACKAGE_STRING ]; then
     # We apply the patches manually here (instead of bumping the patch level) because
     # some components (boost) fail to compile with a modified gcc version.
     PATCH_DIR=${THIS_DIR}/gcc-${PACKAGE_VERSION}-patches
-    apply_patches 4 $PATCH_DIR
+    apply_patches 5 $PATCH_DIR
   fi
 
   download_gcc_prerequisites

source/gcc/gcc-4.9.2-patches/945-ustat.patch

@@ -0,0 +1,31 @@
+--- gcc-4.9.2.orig/libsanitizer/sanitizer_common/sanitizer_platform_limits_posix.cc	2019-12-17 17:56:37.654678258 -0600
++++ gcc-4.9.2/libsanitizer/sanitizer_common/sanitizer_platform_limits_posix.cc	2019-12-17 17:58:23.089867685 -0600
+@@ -81,7 +81,6 @@
+ #include <sys/statvfs.h>
+ #include <sys/timex.h>
+ #include <sys/user.h>
+-#include <sys/ustat.h>
+ #include <linux/cyclades.h>
+ #include <linux/if_eql.h>
+ #include <linux/if_plip.h>
+@@ -163,7 +162,19 @@ namespace __sanitizer {
+   unsigned struct_old_utsname_sz = sizeof(struct old_utsname);
+   unsigned struct_oldold_utsname_sz = sizeof(struct oldold_utsname);
+   unsigned struct_itimerspec_sz = sizeof(struct itimerspec);
+-  unsigned struct_ustat_sz = sizeof(struct ustat);
++// Use pre-computed size of struct ustat to avoid <sys/ustat.h> which
++// has been removed from glibc 2.28.
++#if defined(__aarch64__) || defined(__s390x__) || defined (__mips64) \
++  || defined(__powerpc64__) || defined(__arch64__) || defined(__sparcv9) \
++  || defined(__x86_64__)
++#define SIZEOF_STRUCT_USTAT 32
++#elif defined(__arm__) || defined(__i386__) || defined(__mips__) \
++  || defined(__powerpc__) || defined(__s390__)
++#define SIZEOF_STRUCT_USTAT 20
++#else
++#error Unknown size of struct ustat
++#endif
++  unsigned struct_ustat_sz = SIZEOF_STRUCT_USTAT;
+ #endif // SANITIZER_LINUX
+
+ #if SANITIZER_LINUX && !SANITIZER_ANDROID