Grabbed from the diff between icu 49.1.2 and icu 51.1
https://bugs.gentoo.org/show_bug.cgi?id=466700

Fix (bundled) icu build on sparc.


Index: texlive-20120701-source/libs/icu/icu-49.1/common/unicode/platform.h
===================================================================
--- texlive-20120701-source.orig/libs/icu/icu-49.1/common/unicode/platform.h
+++ texlive-20120701-source/libs/icu/icu-49.1/common/unicode/platform.h
@@ -349,6 +349,10 @@
 #elif U_PLATFORM == U_PF_OS390 || U_PLATFORM == U_PF_OS400
     /* These platforms do not appear to predefine any endianness macros. */
 #   define U_IS_BIG_ENDIAN 1
+#elif defined(sparc) || defined(__sparc) || defined(__sparc__)
+   /* Some sparc based systems (e.g. Linux) do not predefine any endianness
+    * macros. */
+#   define U_IS_BIG_ENDIAN 1
 #else
 #   define U_IS_BIG_ENDIAN 0
 #endif