Update latest release section for 0.49.0

[Sreekala-Gopakumar]

What's New update for the website, for 0.49.0 (February 2025)

[Sreekala-Gopakumar]

First draft (0.48.0 content is live at https://www.eclipse.org/openj9). Note: this isn't an exhaustive list of all the changes, just the main ones:

Eclipse OpenJ9 version 0.49.0 released

February 2025

We're pleased to announce the availability of Eclipse OpenJ9™ v0.49.0.

This release supports OpenJDK 8,11, 17, 21, and 23. For more information about supported platforms and OpenJDK versions, see Supported environments.

Other updates in this release include the following:

• The shared classes cache generation number is incremented because of a new flag J9AccClassIsShared that is added to ROMClasses to indicate whether a ROMClass was loaded from a shared classes cache or from a VM.
• A new shared classes cache suboption, -Xshareclasses:extraStartupHints=<number> is added to adjust the number of startup hints that can be stored in a shared cache.
• subAllocator related -Xgc options are added to control the compressed reference allocation.
• A new option, -XX:[+|-]FlightRecorder is added to enable or disable the Java Flight Recorder (JFR) tool in the VM.

To read more about these and other changes, see the OpenJ9 user documentation.

Performance highlights include:

[Sreekala-Gopakumar]

@pshipton @vijaysun-omr - Are there any performance updates that you want to highlight in the website?
Any other what's new update to be added here? Thanks!