`GenTreeAddrMode` has implicit truncation for its `gtOffset` field

[tannergooding]

The constructor takes in and stores a ssize_t offset: https://github.com/dotnet/runtime/blob/main/src/coreclr/jit/gentree.h#L7089

However, it returns an int Offset() which may result in implicit truncation and loss of data: #86400

We should likely change the signature to take in an int and ensure that all taken offsets are in range.

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Issue Details

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The constructor takes in and stores a ssize_t offset: https://github.com/dotnet/runtime/blob/main/src/coreclr/jit/gentree.h#L7089

However, it returns an int Offset() which may result in implicit truncation and loss of data: #86400

We should likely change the signature to take in an int and ensure that all taken offsets are in range.

Author:	tannergooding
Assignees:	-
Labels:	area-CodeGen-coreclr, untriaged
Milestone:	-