RFR (trivial): 8216285: Enable inlining of CollectedHeap::obj-/array-/class_allocate

[Claes Redestad]

Hi,

inlining these trivial methods is beneficial on microbenchmarks while
size-neutral w.r.t. compiled binary.

Bug:    https://bugs.openjdk.java.net/browse/JDK-8216285
Webrev: http://cr.openjdk.java.net/~redestad/8216285/open.00/

Testing: tier1

Thanks!

/Claes