Add utilities for converting from Host endianity to big endian and little endian formats for the va…

runtime/vm/os_android.cc

Index: runtime/vm/os_android.cc
===================================================================
--- runtime/vm/os_android.cc	(revision 21569)
+++ runtime/vm/os_android.cc	(working copy)
@@ -8,6 +8,7 @@
 #include "vm/os.h"
 
 #include <android/log.h>  // NOLINT
+#include <endian.h>  // NOLINT
 #include <errno.h>  // NOLINT
 #include <limits.h>  // NOLINT
 #include <malloc.h>  // NOLINT
@@ -323,6 +324,36 @@
 }
 
 
+uint16_t HostToBigEndian16(uint16_t value) {
+  return htobe16(value);
+}
+
+
+uint32_t HostToBigEndian32(uint32_t value) {
+  return htobe32(value);
+}
+
+
+uint64_t HostToBigEndian64(uint64_t value) {
+  return htobe64(value);
+}
+
+
+uint16_t HostToLittleEndian16(uint16_t value) {
+  return htole16(value);
+}
+
+
+uint32_t HostToLittleEndian32(uint32_t value) {
+  return htole32(value);
+}
+
+
+uint64_t HostToLittleEndian64(uint64_t value) {
+  return htole64(value);
+}
+
+
 void OS::Print(const char* format, ...) {
   va_list args;
   va_start(args, format);