FULL PRODUCT VERSION :
java version "9-ea"
Java(TM) SE Runtime Environment (build 9-ea+151)
Java HotSpot(TM) 64-Bit Server VM (build 9-ea+151, mixed mode)

ADDITIONAL OS VERSION INFORMATION :
Microsoft Windows [Version 6.1.7601]

A DESCRIPTION OF THE PROBLEM :
Abbreviated months such as "Jan", "Feb", etc, are throwing unparseable date errors in Java 9 when using the Australia locale (en_AU).

REGRESSION. Last worked in version 8u102

ADDITIONAL REGRESSION INFORMATION:
java version "1.7.0_111"
Java(TM) SE Runtime Environment (build 1.7.0_111-b32)
Java HotSpot(TM) 64-Bit Server VM (build 24.111-b32, mixed mode)

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Attempt to parse any date containing the "Month in year (context sensitive)" pattern using SimpleDateFormat with the en_AU locale.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
The date would be successfully parsed.
ACTUAL -
ParseException, date cannot be parsed with Australian locale.

ERROR MESSAGES/STACK TRACES THAT OCCUR :
Exception in thread "main" java.text.ParseException: Unparseable date: "31/AUG/2016"
        at java.base/java.text.DateFormat.parse(DateFormat.java:366)

REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
import java.util.Locale;
import java.text.ParseException;
import java.text.SimpleDateFormat;

class AUDate {

public static void main(String[] args) throws ParseException {
System.out.println("Parsing using ROOT locale...");
SimpleDateFormat rootDateFormat = new SimpleDateFormat("dd/MMM/yyyy", Locale.ROOT);
rootDateFormat.parse("31/AUG/2016"); // OK

System.out.println("Parsing using US locale...");
SimpleDateFormat usDateFormat = new SimpleDateFormat("dd/MMM/yyyy", Locale.US);
usDateFormat.parse("31/AUG/2016"); // OK

System.out.println("Parsing using AU locale...");
SimpleDateFormat auDateFormat = new SimpleDateFormat("dd/MMM/yyyy", Locale.forLanguageTag("en-AU"));
auDateFormat.parse("31/AUG/2016"); // Fail
}

}
---------- END SOURCE ----------

CUSTOMER SUBMITTED WORKAROUND :
Pass -Djava.locale.providers=JRE,SPI to use old locale date as of JDK 7/8.

Alternatively the CLDR for en_AU seems to think we abbreviate our dates with a fullstop - e.g.

31/AUG/2016 throws an exception
31/AUG./2016 works