RFR: 8221981: Simplify Map/List/Set.of() implementation

[Stuart Marks]

On 4/4/19 3:29 AM, Claes Redestad wrote:
> current implementations of the empty static factories (Map.of(), ...)
> delegate to static methods in java.util.ImmutableCollections. This
> indirection isn't really useful and adds a very small startup cost.
> 
> Bug:    https://bugs.openjdk.java.net/browse/JDK-8221981
> Webrev: http://cr.openjdk.java.net/~redestad/8221981/open.00/
> 
> Testing: tier1-2, verified a tiny improvement in startup profiles

Changes look good, thanks.

s'marks