RFR(XS): 8153835: Fix range of flag MaxDirectMemorySize which is parsed at jlong.

[Gerard Ziemski]

Thank you for the review Goetz!

Can I have a second review for this simple fix please?

In this fix we set the max range value to max_jlong (and change the type to uint64_t) since it gets assigned to MaxDirectMemorySize property that is later parsed as “java long” (in java.base/VM.java:290)

https://bugs.openjdk.java.net/browse/JDK-8153835
http://cr.openjdk.java.net/~gziemski/8153835_rev1/

Passes JPRT hotspot and RBT hotspot/test/runtime/CommandLine/OptionsValidation


cheers