os::print_hex_dump prints incorrectly for big endian platforms and unit sizes larger than 1

Matthias wrote:

On AIX, we start today seeing failures , is this maybe related ?
Test gtest/NMTGtests.java#nmt-off
java.lang.AssertionError: gtest execution failed; exit code = 2. the failed tests: [os::test_print_hex_dump_vm, os::test_print_hex_dump_vm, os::test_print_hex_dump_vm, os::test_print_hex_dump_vm, os::test_print_hex_dump_vm, os::test_print_hex_dump_vm]
at GTestWrapper.main(GTestWrapper.java:98)
at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)
at java.base/java.lang.reflect.Method.invoke(Method.java:580)
at com.sun.javatest.regtest.agent.MainActionHelper$AgentVMRunnable.run(MainActionHelper.java:333)
at java.base/java.lang.Thread.run(Thread.java:1570)


stdout contains :
test/hotspot/gtest/runtime/test_os.cpp:174: Failure
Value of: buf
Expected: has substring "0001 0203 0405 0607 0809 0a0b 0c0d 0e0f"
  Actual: "0x0000000115739c70: 0000 0102 0304 0506 0008 090a 0b0c 0d0e\n0x0000000115739c80: 0010 1112 1314 1516 0018 191a 1b1c 1d1e\n0x0000000115739c90: 0020 2122 2324 2526 0028 292a 2b2c 2d2e\n0x0000000115739ca0: 0030 3132 3334 3536 0038 393a 3b3c 3d3e\n0x00000"
test/hotspot/gtest/runtime/test_os.cpp:174: Failure
Value of: buf
Expected: has substring "00010203 04050607 08090a0b 0c0d0e0f"
  Actual: "0x0000000115739c70: 00000000 01020304 00000008 090a0b0c\n0x0000000115739c80: 00000010 11121314 00000018 191a1b1c\n0x0000000115739c90: 00000020 21222324 00000028 292a2b2c\n0x0000000115739ca0: 00000030 31323334 00000038 393a3b3c\n0x0000000115739cb0: 0"
test/hotspot/gtest/runtime/test_os.cpp:174: Failure
Value of: buf
Expected: has substring "0001020304050607 08090a0b0c0d0e0f"
  Actual: "0x0000000115739c70: 0000000000000000 0000000000000008\n0x0000000115739c80: 0000000000000010 0000000000000018\n0x0000000115739c90: 0000000000000020 0000000000000028\n0x0000000115739ca0: 0000000000000030 0000000000000038\n0x0000000115739cb0: 000000000"
test/hotspot/gtest/runtime/test_os.cpp:174: Failure
Value of: buf
Expected: has substring "0001 0203 0405 0607 0809 0a0b 0c0d 0e0f"
  Actual: "0x0000000115739c70: 0000 0102 0304 0506 0008 090a 0b0c 0d0e\n0x0000000115739c80: 0010 1112 1314 1516 0018 191a 1b1c 1d1e\n0x0000000115739c90: 0020 2122 2324 2526 0028 292a 2b2c 2d2e\n0x0000000115739ca0: 0030 3132 3334 3536 0038 393a 3b3c 3d3e\n0x00000"
test/hotspot/gtest/runtime/test_os.cpp:174: Failure
Value of: buf
Expected: has substring "00010203 04050607 08090a0b 0c0d0e0f"
  Actual: "0x0000000115739c70: 00000000 01020304 00000008 090a0b0c\n0x0000000115739c80: 00000010 11121314 00000018 191a1b1c\n0x0000000115739c90: 00000020 21222324 00000028 292a2b2c\n0x0000000115739ca0: 00000030 31323334 00000038 393a3b3c\n0x0000000115739cb0: 0"
test/hotspot/gtest/runtime/test_os.cpp:174: Failure
Value of: buf
Expected: has substring "0001020304050607 08090a0b0c0d0e0f"
  Actual: "0x0000000115739c70: 0000000000000000 0000000000000008\n0x0000000115739c80: 0000000000000010 0000000000000018\n0x0000000115739c90: 0000000000000020 0000000000000028\n0x0000000115739ca0: 0000000000000030 0000000000000038\n0x0000000115739cb0: 000000000"
[ FAILED ] os.test_print_hex_dump_vm (4 ms)