OffHeap Changes

[rmnattas]

Changes to support OffHeap

• Add pinning array support for OffHeap by storing the pinning array in node extension.
• Add OffHeap support in constrainAnyIntLoad for valuePropagation
• Update LoopVersioner code to support OffHeap

[rmnattas]

Failure in CI JitBuilder testing, looking into it

Assertion failed at /home/vsts/work/1/s/compiler/il/OMRNode.cpp:212: self()->hasSymbolReference() + self()->hasRegLoadStoreSymbolReference() + self()->hasBranchDestinationNode() + self()->hasBlock() + self()->hasArrayStride() + self()->hasPinningArrayPointer() + self()->hasDataType() <= 1
_unionPropertyA union is not disjoint for this node aloadi (0x55a674c83880):
has({SymbolReference, ...}, ..., DataType) = ({1,0},0,0,0,1,0)

[rmnattas]

Fixed

[vijaysun-omr]

For the loop versioner commit, I would like @jdmpapin to also review.

There is a typo in that loop versioner commit message : "to use the chilid of aloadi tree"

[rmnattas]

Changes for enabling pinning array for all nodes causes a failure now, looking at it. Also working on the comments (not sure of tree shapes myself as I didn't do the code but will understand and comment).

[rmnattas]

I updated the VPHandler code and added comments, please review changes. Also added a i2l check for the stride==1 case which didn't exist originally but I believe is needed.

[vijaysun-omr]

The additional comments and changes help. The code looks somewhat easier to follow. I'll wait for Devin's review as well

[vijaysun-omr]

Jenkins build all

[vijaysun-omr]

Checks have passed. Merging.