XJC compiler produces unstable output given the same input

[LanceAndersen]

Previously tracked via: https://bugs.openjdk.java.net/browse/JDK-8169102

A DESCRIPTION OF THE REQUEST :
When given the same schema file, XJC produces Java source files with a slightly different order of fields.

JUSTIFICATION :
Stable XJC output can help reduce build times in large projects since there will be no unnecessary recompilations of Java source files generated by the XJC compiler.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
Give the same input, XJC should produce the same output (with an exception of optionally included timestamp) every time it runs.
ACTUAL -
The output varies slightly in the order of class fields.