RFC: JDK-8290706: Remove the support for inline contiguous allocations

[Aleksey Shipilev]

Hi there,

This is a cleanup that I was itching to do for a while:
   https://bugs.openjdk.org/browse/JDK-8290706

I have a draft change for it, and it removes about 1 KLOC, mostly from platform-specific code. 
Before I submit that PR for review, please let me know if you have strong opinions about (not) doing 
this.

-- 
Thanks,
-Aleksey